COVID-19 Situation Report
Editor: Alyson Browett, MPH

Contributors: Clint Haines, MS; Natasha Kaushal, MSPH; Amanda Kobokovich, MPH; Christina Potter, MSPH; Matthew Shearer, MPH; Marc Trotochaud, MSPH; and, Rachel A. Vahey, MHS.
UPCOMING WEBINAR Please join us for a COVID-19 Testing Toolkit webinar, Johns Hopkins University (JHU) Testing Strategy, on Tuesday, May 3 at 2:00pm ET. The 3 panelists, leaders serving across the university, will discuss how JHU developed and implemented its COVID-19 testing strategies for faculty, staff, and students; how JHU adapted its strategy over time; and how JHU is preparing for commencement. Register online here.
EPI UPDATE The WHO COVID-19 Dashboard reports 509 million cumulative cases and 6.2 million deaths worldwide as of April 27. As expected, the number of cumulative cases surpassed 500 million on April 14. The global weekly incidence decreased for the fifth consecutive week—down 19% from the previous week—to the lowest weekly total since mid-December 2021. Most regions continued to report decreasing trends in weekly incidence. Africa’s weekly total increased 32% over the previous week, which appears to be largely driven by the surge in South Africa. Weekly incidence also increased in the Americas, up 8.7% over the previous week. The trend in reported global weekly mortality decreased for a third consecutive week, down 19% from the previous week. 

Global Vaccination
As of April 18, WHO reported 11.4 billion cumulative vaccine doses administered globally, with 3.82 billion individuals receiving at least 1 dose, and 3.35 billion fully vaccinated*. Analysis from Our World in Data indicates that the overall trend in global daily vaccinations continues to decline overall—down from nearly 40 million doses per day in late December 2021—although the global average increased from 10.7 million doses per day last week to 11.7 million on April 27**. The trend continues to closely follow that in Asia. Our World in Data estimates that there are 5.13 billion vaccinated individuals worldwide (1+ dose; 65.2% of the global population) and 4.64 billion who are fully vaccinated (59.0% of the global population). A total of 1.84 billion booster doses have been administered globally.
*The WHO data for cumulative global vaccinated individuals decreased substantially from the previous week—down from 5.1 billion with 1+ dose and 4.58 billion fully vaccinated. It is not immediately clear why the current numbers are lower.
**The average daily doses administered may exhibit a sharp decrease for the most recent data, particularly over the weekend, which indicates effects of reporting delays. In an effort to reflect the longer-term trends, the numbers reported here may not correspond to the most recent data.

UNITED STATES
The US CDC is reporting 80.9 million cumulative cases of COVID-19 and 989,408 deaths. The average daily incidence has nearly doubled from the recent low of 24,982 new cases per day on April 4 to 48,692 on April 26. The daily mortality continues to decline, down to 299 deaths per day—the first day below 300 since July 23, 2021.* Notably, new COVID-19 hospital admissions continue to trend upwards, with an increase of 17.6% over the past week. 
*Changes in state-level reporting may affect the accuracy of recently reported data, particularly over weekends. In an effort to reflect the longer-term trends, the numbers reported here may not correspond to the most recent dates.

US Vaccination
The US has administered 574 million cumulative doses of SARS-CoV-2 vaccines. After a slight increase starting in late March, following US FDA authorization of a second booster dose, daily vaccinations are once again declining, down from 485,000 doses per day on April 12 to 394,000 on April 21 (-18.6%). A total of 257 million individuals have received at least 1 vaccine dose, which corresponds to 77.5% of the entire US population. Among adults, 89.0% have received at least 1 dose, as well as 27.7 million children under the age of 18. A total of 219 million individuals are fully vaccinated**, which corresponds to 66.1% of the total population. Approximately 76.0% of adults are fully vaccinated, as well as 23.1 million children under the age of 18. A total of 100.3 million individuals have received an additional or booster dose. This corresponds to 45.7% of fully vaccinated individuals, including 68.5% of fully vaccinated adults aged 65 years or older. Only 49.5% of individuals eligible for a first booster dose have received one.
*Due to delays in reporting, estimates for the average daily doses administered are less accurate for the most recent several days. 
**Full original course of the vaccine, not including additional or booster doses.

VACCINES FOR YOUNGEST CHILDREN Moderna this morning submitted a request with the US FDA for Emergency Use Authorization (EUA) of its SARS-CoV-2 vaccine for children ages 6 months to under age 6. The submission is based on data from the Phase 2/3 KidCOVE study, which tested a 2-dose primary series in young children using a low-dose 25 μg version of the vaccine. According to Moderna, the lower dosage led to a similar immune response in young children as the higher 100 μg 2-dose primary series in adults, with a favorable safety profile. In a revised analysis based on data first released in March, the data showed the vaccine was 51% effective at preventing symptomatic COVID-19 in the youngest children, ages 6 months to under 2 years, and 37% effective at preventing symptomatic disease in children ages 2 through 5. These results were collected during the Omicron surge and showed similar declines in protection as adults due to the variant’s ability to partially evade vaccine-induced immunity. Moderna also is expected to soon seek authorization of its vaccine for children ages 6-11, as well as file an update to its EUA for adolescents aged 12-17. The FDA has not ruled on the company’s EUA request for adolescents, submitted in June 2021, citing concerns over the rare side effect of myocarditis and pericarditis, particularly in teen boys. Currently, only the Pfizer-BioNTech vaccine is authorized for children aged 5-11.

A top FDA official this week suggested the agency has not yet reviewed data on SARS-CoV-2 vaccines for the youngest children because the manufacturers have not completed their EUA applications. The agency is expected to release a timeline for expert review this week. Despite growing pressure, a decision on whether to authorize a vaccine for the nation’s 18 million youngest children likely will not happen until June. Moderna is expected to complete its EUA submission for the youngest children next week, and Pfizer and BioNTech plan to complete their application for a 3-dose vaccine regimen for children younger than 5 years in late May or early June. A White House official suggested the FDA might prefer to review both applications simultaneously in order to compare the vaccines side-by-side and simplify communication about the vaccines if and when one or both are authorized for young children. 

BOOSTERS FOR CHILDREN AGES 5-11 Pfizer and BioNTech on April 26 submitted a request to the US FDA for Emergency Use Authorization (EUA) of a booster dose of the companies’ SARS-CoV-2 vaccine for children aged 5 to 11 years. The booster would be a third shot of the same 10 µg dosage used in the 2-dose primary series, administered about 6 months after the second dose. Currently, third doses of the Pfizer-BioNTech vaccine are authorized for children aged 5 to 11 who are moderately to severely immunocompromised, and booster doses are authorized for all individuals aged 12 years and older, who receive a higher dose (30 µg). Experts are divided over whether a booster dose is necessary in healthy children. Some say data show vaccine effectiveness wanes over time and support the use of boosters in children to maintain a higher level of protection. Others remain skeptical, contending that 2 doses continue to protect recipients against serious illness from the currently circulating SARS-CoV-2 variants and because children have an overall lower risk of severe disease and hospitalization from COVID-19. Only 28% of children aged 5 to 11 years are fully vaccinated, signaling that demand for a booster dose among this age group likely would be low. Pfizer and BioNTech also plan to submit data for booster authorization to the European Medicines Agency (EMA) and other regulatory agencies worldwide in the coming weeks.

ANNUAL BOOSTERS The US FDA has authorized second booster, or fourth, doses for parts of the US population, raising questions over how frequently boosters will be required moving forward. Several companies, including Novavax and Moderna, have begun initiatives to develop joint influenza and COVID-19 shots, creating what would be a new annual vaccine administered each fall. But several US scientists and researchers recently urged more involved dialogue regarding future plans for the use of SARS-CoV-2 vaccine boosters, pushing back on the idea of annual boosters and calling for more data on the value of annual SARS-CoV-2 booster doses. While there is no evidence suggesting any harm from additional booster doses, the experts have shared several concerns that could stem from a policy requiring annual vaccinations. First, they worry that an emphasis on boosters diminishes the long-lasting protection that current vaccine doses provide against severe COVID-19 disease. Second, experts worry that a lack of evidence in regulatory decision making could set a dangerous precedent moving forward. The group specifically urged the FDA to measure T-cell responses, in addition to antibody responses, when conducting SARS-CoV-2 vaccine trials. Lastly, they noted the lack of response for both first and second booster doses signals fatigue from the US public. More than 100 million US residents have received the first COVID-19 booster, roughly 50% of eligible people. Some worry that “booster fatigue” will be a problem, adding to calls for a more prudent, data-driven approach to annual boosters. 

US SEROPREVALENCE A study published April 26 in the US CDC’s Morbidity and Mortality Weekly Report (MMWR) estimates that 58% of the US population, including 75% of children, have been infected with SARS-CoV-2. Many of those infections occurred during the winter’s Omicron surge. The study reports on data from national commercial laboratories across all 50 states, Washington, DC, and Puerto Rico. Between September 2021 and February 2022, labs conducted convenience samples on blood specimens that were submitted for clinical testing in their labs, excluding samples that were testing for SARS-CoV-2 antibodies upon initial receipt. The median sample size for the group of labs was 73,869 each month, with a drop in the number of tests to 45,810 in February 2022, likely caused by disruptions from the surge in domestic infections fueled by the Omicron variant. The research team weighted samples by demographic data to produce estimates of seroprevalence. 

The team saw a slight, but steady, increase in seroprevalence between September and December 2021, increasing between 0.9-1.9% every 4 weeks. At the end of this collection period, the seroprevalence across the US sample was estimated to be 33.5%. Between December 2021 and February 2022, at the height of the Omicron surge, the team observed a spike in national seroprevalence, rising from 33.5% to 57.7%. Notably, during this period, children aged 0-11 saw an increase from 44.2% to 75.2% and those aged 12-17 saw a similar increase from 45.6% to 74.2%. Adult populations saw spikes in seroprevalence from 36.5% to 63.7% for individuals aged 18-49, 28.8% to 49.8% for those 50-64, and 19.1% to 33.2% among those aged 65 and older. The researchers noted several limitations in their study design, including restrictions of applicability tied to convenience sampling; limited race and ethnicity data; the potential for sampling bias due to the setting of sample collection; and the possibility that infection following vaccination resulted in reduced antibody titers.  

SARS-CoV-2 testing is only able to catch a fraction of cases occurring in the country, so serosurveys present an opportunity to better understand the scale of infections. Still, the study may not represent a full picture of COVID-19 in the country, nor does it indicate whether or not individuals with SARS-CoV-2 antibodies have persistent immunity to new infections. CDC Director Dr. Rochelle Walensky noted the study’s results and vaccine uptake show an increased level of community protection from SARS-CoV-2. She added that vaccination remains key in creating a more resilient population, urging those who remain unvaccinated, including those previously infected, to get vaccinated. 

PANDEMIC TRANSITIONING COVID-19 remains a pandemic, constituting a serious health threat in many parts of the world. Even as COVID-19-related deaths reach their lowest point since the pandemic began, several Asian nations are experiencing their largest surges to date and countries in Africa—which currently is experiencing an increase in cases—continue efforts to ramp up vaccination programs. But other countries, particularly in North America and Europe, are taking steps to move beyond an emergency phase, relaxing public health mitigation guidelines and reducing or eliminating COVID-19 funding from budgets. Global health experts note the pandemic is at a critical juncture, as wealthy nations—criticized for not doing enough to help low- and middle-income countries throughout the pandemic—cut back even more.

The EU this week declared an end to the COVID-19 emergency, saying the disease should be treated similarly to influenza. Denmark announced an end to its widespread vaccination program, saying “the epidemic has reversed.” However, the Danish Health and Medicines Authority said additional vaccinations against COVID-19 likely will be needed in the future as new variants emerge. In the US, debate over additional funding for the pandemic response is at a standstill in the US Congress, and the administration of US President Joe Biden has warned that without new funds, the nation’s domestic and international response efforts will falter. White House Chief Medical Advisor Dr. Anthony Fauci said this week that the US is “out of the pandemic phase,” but later clarified those remarks, noting the pandemic is ongoing but that the US is in “a transitional phase,” moving out of an acute emergency state and into a more controlled phase. Mexico’s government declared the nation has moved into an endemic stage, and authorities will treat COVID-19 as a seasonal disease. Still, as long as COVID-19 outbreaks continue, the virus will continue to evolve and potentially develop the ability to further evade vaccine-induced or natural immunity, creating high levels of uncertainty around the future of the pandemic.  

GLOBAL DECLINE IN TESTING As the pandemic continues, the WHO is receiving less testing data, which is compounding challenges in monitoring epidemiological trends and emerging variants. Earlier this week, WHO Director-General Dr. Tedros Adhanom Ghebreyesus called on governments to maintain sufficient SARS-CoV-2 surveillance, in part to ensure that the WHO has the data necessary to track the pandemic and provide guidance. Global testing has reportedly declined by 70-90% over the past 4 months, although the exact cause remains uncertain. Over that period, the global daily incidence fell from a record high of 3.4 million new cases per day in late January to fewer than 700,000, a decline of 80%. It is difficult to get a reliable global estimate for test positivity, because it is not reported consistently by many countries; however, the trends vary considerably among countries with the highest cumulative incidence. Test positivity in some countries—including Argentina, India, Russia, Turkey, and the United States*—has declined substantially from peaks in January-February, while it remains elevated or has increased sharply in others—such as Brazil, France, Germany, Netherlands, South Korea, and Vietnam. Without additional data, the extent to which the decline in testing is a function of slowing transmission, changes in national policies or capacities, or other factors is unclear. One potential factor is the expanded availability of at-home rapid tests in many countries. Many of these test results (positive and negative) go unreported to public health authorities, and therefore, to the WHO. As the pandemic continues, epidemiological and genomic surveillance are needed to provide critical data for health and elected officials at all levels of government.
*Although the US estimate has more than doubled since its recent low in mid-March.

TWITTER & MISINFORMATION The WHO has worked with social media platforms prior to and throughout the COVID-19 pandemic to mitigate the spread of online misinformation and disinformation. With the news that billionaire Elon Musk has reached a US$44 billion deal to purchase Twitter—a previously publicly owned influential platform with 217 million daily active users worldwide—WHO officials are warning of the dangers of health and vaccine misinformation on social media. During a briefing this week, several WHO officials said Musk—who has said he plans to hold up free-speech standards similar to those of the US government—has a “huge responsibility” to combat health-related falsehoods, which can lead to mistrust, confusion, or risk-taking and potentially prolong or intensify disease outbreaks. 

According to the WHO, false information is 70% more likely to get shared than accurate news on social media. In a paper published April 26 in Nature Scientific Reports, researchers from Indiana University and the Polytechnic University of Milan suggest that online misinformation posted during the pandemic is associated with early COVID-19 vaccination hesitancy and refusal. The researchers underscored the importance of combating online misinformation, writing that although people in the US have a constitutional right to free speech, providing access to trustworthy information is vital to maintaining public health. Another study from Germany, published April 27 in BMC Public Health, reinforces these findings, concluding that online misinformation is an important reason for vaccination refusal and providing access to quality information sensitive to the needs of the target audience is vital. It is unclear how or if Musk will continue Twitter’s work with the WHO or other health agencies, and many fear that his insistence on free speech could create a fertile platform for the dissemination of even more health misinformation, myths, and conspiracy theories. 

MEASLES Over the past 2 years, the COVID-19 pandemic interrupted routine childhood vaccinations globally, resulting in a backslide of immunization efforts in many regions. As a potential signal of future vaccine-preventable disease outbreaks, the number of reported measles cases increased 79% during the first 2 months of 2022, compared to the same period in 2021, according to UNICEF and the WHO. In 2020, 23 million children missed out on routine childhood immunizations, the highest number since 2009. The agencies urged nations to rapidly get vaccination programs back on track to help mitigate the impacts of missed shots, the effects of which will be felt for decades.  

VIRAL SPILLOVERS At least 10,000 virus species have the ability to infect humans, but most of those are currently silently circulating in mammalian species other than humans. But as the planet warms and humans are forced to move into new habitats, the risk that these diseases will pass from their animal hosts to humans increases enormously over the next 50 years, according to research published today in Nature. Using a computational model, the researchers estimate that more than 4,000 spillover events could occur among 3,139 species as the climate changes and their habitats overlap. This situation is already happening, and some experts say the world is moving from the Anthropocene era—when humans dominated influence over the Earth’s environment—into a Pandemicene, an era characterized by diseases’ influence on humanity. Several SARS-CoV-2 spillover events have been documented, including one involving mink in the US and another involving white-tailed deer in Canada. Hence, global health experts are promoting a One Health approach to tracking COVID-19 and other viruses and warning that more pandemics will occur as the Earth warms, making pandemic preparedness one of the most urgent issues of our time.