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.
EPI UPDATE The WHO COVID-19 Dashboard reports 504 million cumulative cases and 6.2 million deaths worldwide as of April 20. As expected, the number of cumulative cases surpassed 500 million on April 14.  

The global weekly incidence decreased for the fourth consecutive week, down 22% from the previous week. Most regions reported decreasing trends in weekly incidence last week, except for Africa, which remained relatively stable from the previous week (+0.23%). 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 11.3 billion cumulative vaccine doses administered globally, with 5.1 billion individuals receiving at least 1 dose, and 4.58 billion fully vaccinated. Analysis from Our World in Data indicates that the overall trend in global daily vaccinations continues to decline, down from nearly 40 million doses per day in late December 2021 to 10.7 million on April 20, a decrease of 70% over that period.* The trend continues to closely follow that in Asia. Our World in Data estimates that there are 5.12 billion vaccinated individuals worldwide (1+ dose; 65% of the global population) and 4.63 billion who are fully vaccinated (58.76% of the global population). A total of 1.77 billion booster doses have been administered globally.
*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.

The US CDC is currently reporting 80.6 million cumulative cases of COVID-19 and 987,034 deaths. The average 7-day daily incidence was 40,985 on April 19, an increase of nearly 40% since a recent low of 24,845 on March 29. Average daily mortality appears to have declined over the past week, with a 7-day average of 385 on April 19, down slightly from 459 on April 12, the date of our last report.* Notably, the 7-day moving average number of new hospital admissions of people with confirmed COVID-19 continues to trend upwards, up 7.2% over the prior 7-day average, for the week ending April 18, reflecting the increasing trend in incidence. 
*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 570.5 million cumulative doses of SARS-CoV-2 vaccines. Daily vaccinations have mostly leveled off over the past 2 weeks, with a slight increase from 455,258 on April 6 to 459,655 on April 14. A total of 256.9 million individuals have received at least 1 vaccine dose, which corresponds to 77.4% of the entire US population. Among adults, 88.8% have received at least 1 dose, as well as 27.6 million children under the age of 18. A total of 219 million individuals are fully vaccinated**, which corresponds to 66% of the total population. Approximately 75.9% of adults are fully vaccinated, as well as 23 million children under the age of 18. A total of 99.7 million individuals have received an additional or booster dose. This corresponds to 45.5% of fully vaccinated individuals, including 68.1% of fully vaccinated adults aged 65 years or older. Only about 50% of those 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.

US TRAVEL MASK MANDATE The US Department of Justice has filed an appeal seeking to reverse an April 18 ruling by a federal District Court judge in Florida that voided a national mask mandate for mass transit. The federal judge ruled that the US CDC’s mask mandate exceeded the agency’s statutory authority, immediately ending the requirement put in place to reduce the risk of SARS-CoV-2 among travelers on public transportation and in transit stations. The ruling left decisions to enforce mask wearing up to individual transportation companies and transit authorities. Following the ruling, the Transportation Security Administration (TSA) said it will not enforce its mask mandate in transportation settings, as it awaits future court proceedings. Additionally, most major domestic airlines rescinded their mask requirements, as did Amtrak, rideshare companies Uber and Lyft, and several major transit authorities. The White House called the ruling “disappointing,” especially as the number of new COVID-19 cases in the US begin to rise again. Reactions were more mixed among the public and transportation employees, with some flight attendants gleefully announcing mid-flight that passengers could remove their masks. Other airline employees, TSA agents, and members of the public reacted with confusion and concern, especially for those who are ineligible for vaccination or at higher risk of severe disease. 

As such, the CDC issued a statement calling the mandate “necessary for the public health,” prompting the Department of Justice to appeal the case to the US Court of Appeals for the 11th Circuit. However, federal officials are uncertain how the appeal will be received in this court given its conservative lean. Additionally, some legal experts expressed concern that if the lower court ruling stands, the precedent could severely handicap CDC’s ability to exercise its mandate to protect public health in the future. In the meantime, US residents will face a patchwork of policies that may or may not be enforced by employers, state or local governments, or private businesses. Nevertheless, the science behind mask-wearing as a means of lowering the risk of SARS-CoV-2 transmission in indoor public spaces remains solid, and people who wear high-quality masks can still protect themselves even if others are not masked. 

OMICRON SUBLINEAGES Scientists around the world have been closely monitoring SARS-CoV-2 variants and their relative dominance to better inform response activities. In the US, the original Omicron variant has been displaced by its sublineage BA.2, but now, BA.2 may be competing with BA.2.12.1, its own sublineage. The US CDC estimates that BA.2 makes up 75% of current COVID-19 cases in the US, while BA.2.12.1 makes up 19% of COVID-19 cases. The remaining 6% are attributable to BA.1.1 and B.1.1.529, which have been waning. Initial signs point to Omicron descendent lineages not substantially differing from the original variant in terms of virulence or evasion of immunity. That evidence, relatively higher population immunity for the moment, and warmer weather indicate that there is not a need for panic regarding BA.2.12.1. However, caution and vigilance are warranted. The New York State Department of Health notes that BA.2.12.1, along with another new sublineage, BA.2.12, have contributed to a recent spike in cases in the state’s northern region, estimating the new sublineages have a 23-27% growth advantage over BA.2. 

CDC ADVISORY PANEL ON BOOSTERS Since the US FDA authorized fourth doses, or second boosters, of the Pfizer-BioNTech and Moderna mRNA SARS-CoV-2 vaccines last month for people 50 and older and additional doses for immunocompromised people 12 and older, there has been widespread confusion among some healthcare providers and eligible individuals about when to get the shots and why. Public health officials maintain that continuous vaccination is only a stopgap measure aimed at lowering the risk of hospitalization and death among vulnerable populations, as they work to develop future vaccination strategies. On April 20, the US CDC’s Advisory Committee on Immunization Practices (ACIP) met to consider exactly who might benefit most from additional doses and what the ongoing vaccination strategy will entail, although there were no votes taken on any topics of discussion.

A CDC researcher told the panel that based on current data, individuals who are immunocompromised, live with an immunocompromised person, and those who are at increased risk of severe COVID-19 should consider getting a second booster now, while healthy older adults and those who have had COVID-19 within the past 90 days can wait until later in the year to get an additional shot. The panel also reviewed data showing that incidence of vaccine-associated myocarditis and pericarditis is lower after fourth doses than after the primary 2-dose series; there is no evidence boosters lead to immune tolerance that could cause lower antibody levels; and there is no evidence of immunological imprinting, with patients showing responses to several variants after a booster dose. Several of the panel members encouraged clear communication of a shared vision regarding vaccines, their effectiveness, and their purpose to help prevent “booster fatigue” and reduced public confidence in the vaccines. Others expressed the need for future vaccine strategies to be tailored to different populations, such as providing antibody tests prior to booster administration. 

Additionally, the panel discussed the importance of future SARS-CoV-2 vaccines, including different formulations and platforms. Several companies, including Pfizer-BioNTech and Moderna, are developing variant-specific vaccines, but it is unclear how long testing and manufacturing of any newer vaccine versions might take. Moderna this week released preprint data on a bivalent vaccine candidate, mRNA-1273.211, that contains equal mRNA amounts of spike proteins from the ancestral SARS-CoV-2 strain and the Beta variant and could be used as a booster dose. According to the data—which is not yet peer-reviewed—the vaccine produced stronger, longer-lasting antibody responses against SARS-CoV-2 variants, including Omicron, than the company’s original vaccine. Results from a different Moderna bivalent vaccine candidate that uses mRNA from the original virus and Omicron are expected later this spring. Additionally, Moderna announced it plans to submit a request for Emergency Use Authorization (EUA) of its SARS-CoV-2 vaccine among young children ages 6 months to 5 years by the end of this month.

OMICRON IN CHILDREN A report published April 19 in the US CDC’s Morbidity and Mortality Weekly Report (MMWR) highlights both the importance of SARS-CoV-2 vaccination among children to provide protection against the Omicron variant, as well as racial disparities regarding vaccination coverage and hospitalization during the Omicron surge. Researchers analyzed data from the COVID-19-Associated Hospitalization Surveillance Network to describe characteristics of 1,475 hospitalized children aged 5-11 years, focusing on Omicron predominance from December 19, 2021, to February 28, 2022. Among 397 children hospitalized during Omicron predominance, 87% were unvaccinated, with the cumulative hospitalization rate of unvaccinated children (19.1 per 100,000) over twice as high as that of vaccinated children (9.2 per 100,000). Severe disease was more common among children with diabetes and obesity, although 30% of hospitalized children with COVID-19 had no underlying medical conditions.

The most concerning finding showed that non-Hispanic Black children made up 34% of unvaccinated children and one-third of COVID-19 hospitalizations overall, making it clear that racial disparities of the pandemic extend to children. An analysis published earlier this month by the Kaiser Family Foundation also found that Black children were less likely to be vaccinated than White children in 5 out of 7 states that report vaccination status by race/ethnicity for children aged 5-11 years.

SARS-COV-2 BREATH TEST The US FDA on April 14 issued an Emergency Use Authorization (EUA) for the first COVID-19 diagnostic test that analyzes breath to detect chemical compounds associated with SARS-CoV-2 infection. The InspectIR Covid-19 Breathalyzer is a moderately sized instrument, about the dimension of a piece of carry-on luggage, and must be operated by a qualified and trained worker in a medical office, hospital, or mobile testing site. Test results are returned within about 3 minutes, but positive results should be confirmed with a molecular test. While the breath-based test represents an innovative, noninvasive diagnostic method, restrictions on who can conduct the test, where it can be conducted, and how many samples it can analyze per hour, as well as unknown pricing and a 10-12 week wait for the first devices to come to market, could limit the test’s real-world applications.

GLOBAL COVID-19 SUMMIT The US will co-host a second Global COVID-19 Summit on May 12 to discuss coordination and funding for global vaccination efforts, work to end the emergency phase of the pandemic, and preparedness for future health threats. The US will co-host the virtual summit with Belize, as CARICOM Chair; Germany, holding the G7 Presidency; Indonesia, holding the G20 Presidency; and Senegal as African Union Chair. The first summit was led by the US in September 2021, and this second meeting was originally scheduled for March but was postponed due to Russia’s invasion of Ukraine. Notably, the US might not be able to offer additional support for global vaccination initiatives because the US Congress has not renewed funding for those programs. Without the incentive of more funds for global efforts, the US might face difficulty obtaining further financial commitments from other countries, non-profit organizations, philanthropists, and the private sector.

US EARLY WARNING SYSTEM The US this week launched the Center for Forecasting and Outbreak Analytics (CFA), a US CDC-run initiative its leaders are likening to a National Weather Service for infectious diseases. (Dr. Caitlin Rivers from the Center for Health Security is currently helping lead this new Center at CDC.) With about 100 scientists, CFA will analyze technical data and communicate—in easy-to-understand language—evidence-based policies and strategies for COVID-19 or future infectious disease outbreaks to decisionmakers and the public. The center will work with experts within the government, academia, and the private sector to examine data on new cases, hospitalizations, who is most affected, how transmission is occurring and among whom, and which public health prevention and mitigation strategies work best to reduce transmission. These analyses should help decisionmakers adopt policies that are the most effective and least disruptive. Notably, CFA also is focused heavily on communicating information to the public, particularly vulnerable and historically underserved communities, to help them understand risk and make decisions based on scientific understanding. CFA begins with US$200 million in coronavirus relief funding but will need additional technical and financial support from inside and outside of the federal government as the nation moves beyond the emergency phase of the COVID-19 pandemic.