EPI UPDATE The WHO COVID-19 Dashboard reports 181 million cumulative cases and 3.9 million deaths worldwide as of 7:00am EDT on June 29. After 7 consecutive weeks of declining weekly incidence, the WHO reported an increase of 2.2% compared to the previous week. Weekly incidence increased 10% in Europe, 13% in the Eastern Mediterranean Region, and 34% in Africa. Based on WHO data, the African Region reported its highest weekly total to date. Weekly global mortality decreased for the eighth consecutive week. Global weekly mortality fell by 10% from the previous week, reaching its lowest total since early November 2020.
Global Vaccination
The WHO reported 2.66 billion doses of SARS-CoV-2 vaccines administered globally as of June 28, and 1.07 billion individuals have received at least 1 dose. Analysis from Our World in Data shows that the global daily doses administered reached a new record high of 41.3 million doses per day on June 27 before falling slightly yesterday. The trend continues to be largely driven by vaccination efforts in Asia. Our World in Data estimates that there are 1.8 billion vaccinated individuals (1+ dose) worldwide (23.8% of the global population). There are an estimated 834 million who are fully vaccinated (10.7% of the global population), although reporting is less complete than for other data.
UNITED STATES
The US CDC reported 33.5 million cumulative COVID-19 cases and 601,506 deaths.
US Vaccination
The US has distributed 381 million doses of SARS-CoV-2 vaccines and administered 324 million, and it is administering approximately 614,000 doses per day. A total of 180 million individuals in the US have received at least 1 dose of SARS-CoV-2 vaccine, equivalent to 54.1% of the entire US population. Among adults, 66.1% have received at least 1 dose as well as 8.8 million adolescents aged 12-17. A total of 154 million individuals are fully vaccinated, which corresponds to 46.3% of the total population. Among adults, 57.0% are fully vaccinated, and 6.5 million adolescents aged 12-17 years are fully vaccinated.
VACCINE MIX & MATCH Researchers have posited that mixing multiple different vaccines (e.g., mRNA, viral vector) could yield improved immune response and ease the impact of supply shortages for specific products without sacrificing efficacy. Researchers in the UK, led by a team from the University of Oxford published results from a study that administered 1 dose each of the Pfizer-BioNTech and AstraZeneca-Oxford vaccines. The study, published in The Lancet (preprint), evaluated safety and efficacy data for 830 participants aged 50 years and older, divided into 8 groups. Half of the participants received the 2 doses of either the Pfizer-BioNTech (BNT/BNT) or AstraZeneca-Oxford (ChAd/ChAd) vaccine, administered 28 or 84 days apart. The other half received 1 dose of each vaccine, with half receiving the Pfizer-BioNTech and then AstraZeneca-Oxford (BNT/ChAd) and vice versa (ChAd/BNT) for the other group—also administered either 28 or 84 days apart. This article describes the results for only the participants who received the doses 28 days apart.
The researchers found that the anti-spike IgG levels following the ChAd/BNT regimen were non-inferior to the standard ChAd/ChAd regimen, but the immune response from the BNT/ChAd regimen was not as strong as for the BNT/BNT regimen. While the IgG response in the BNT/ChAd group fell short of the BNT/BNT group, the antibody levels were approximately 5 times higher than the ChAd/ChAd group. The researchers anticipate that the advantage among the groups that received BNT first will decrease in the groups who received the booster dose at 84 days, as the AstraZeneca-Oxford vaccine has been shown to generate an increased immune response with the later booster dose.
No serious adverse events were attributed to vaccination in any study group. This study evaluated only the IgG antibody response and did not estimate efficacy.
VACCINE PROTECTION DURATION One of the major limitations of the accelerated vaccine trial and regulatory review process for SARS-CoV-2 vaccines is that the duration of immunity remains uncertain. A study by researchers at several academic medical centers in the US, published in Nature, found evidence that immunity conferred by the Pfizer-BioNTech vaccine could potentially persist for years. The study included 41 fully vaccinated participants, including 8 who were previously infected with SARS-CoV-2, and blood and lymph node samples were collected before the second dose and up to 15 weeks after the first dose.
The researchers found that the vaccine results in the formation of “germinal centers” in lymph nodes, which serve as a “boot camp” where B cells—the cells that produce antibodies—can evolve to improve their function and recognize a variety of viral genetic sequences. This evolution provides the immune system with increased ability to recognize and respond to emerging variants. The germinal centers in study participants were still “highly active” at 15 weeks, much longer than germinal centers formed following seasonal influenza vaccination. While the study did not explicitly evaluate the Moderna vaccine, the researchers extrapolate their results broadly to mRNA-based vaccines. The researchers did not test the J&J-Janssen vaccine, which is a viral vector vaccine that only requires 1 dose, and it is unclear if that vaccine would generate a similar germinal center response in the absence of a booster dose.
It remains unclear exactly how long the germinal center activity continues for SARS-CoV-2 vaccines, but this initial evidence suggests that vaccine-conferred immunity may not wane as quickly as some have feared. If overall immunity remains high, it could mitigate the need for routine boosters, and if boosters are needed at all, they may be designed to combat specific variants as opposed to waning immunity.
COVID IMPACT ON US LIFE EXPECTANCY As we have covered previously, the morbidity and mortality associated with COVID-19 have resulted in decreased life expectancy* in the US, although the exact degree remains uncertain. Research recently provides evidence that these effects have disproportionately affected racial and ethnic minority populations.
*The underlying assumptions and methods used to estimate life expectancy can make it difficult to interpret the results, and alternative methods can yield markedly different estimates.
One study, published in The BMJ, estimates that life expectancy in the US fell 1.87 years between 2018 and 2020 (78.74 to 76.87 years)**, compared with an average of 0.22 years of life lost in 16 other high-income countries. Compared to peer countries—including the UK, Israel, France, Denmark, Switzerland, and South Korea—the US life expectancy was 1.88 years lower in 2010, and the gap increased to 3.05 years by 2018. Based on the 2020 estimates, the gap widened again to 4.69 years. The researchers also found disproportionate decreases among racial and ethnic minorities in the US. From 2018 to 2020, the decrease in life expectancy among Hispanic populations (3.25 years) was 2.4 times the decrease among non-Hispanic White populations (1.36 years), and the decrease among non-Hispanic Black populations (3.88 years) was 2.9 times higher. The reductions in life expectancy among Hispanic and non-Hispanic Black populations in the US were 18 and 15 times the average change in peer countries, respectively.
**Data from 2019 not included due to a dearth of available life table data in many countries. Estimates were generated manually for 2020 based on age-specific mortality data.
The authors of a study published in JAMA Network Open provide updated estimates to previous estimates of decreasing life expectancy in the US. The researchers estimated US life expectancy at birth from February 1-October 3, 2020, including more than 380,000 COVID-19 deaths. Race/ethnicity data was available for more than 99% of these deaths. The updated analysis estimates that COVID-19 reduced the overall 2020 US life expectancy by 1.31 years, from 78.74 years to 77.43 years. The Latino population had the largest decline (3.03 years), followed by the Black population (1.90 years). These declines were 3.2 and 2.0 times as large as the estimated decline among the White population (0.94), respectively. The researchers expect that COVID-19 deaths through April 2021 will continue to negatively impact US life expectancy, and Black and Latino communities likely will continue to face disproportionate impacts.
MENTAL HEALTH The COVID-19 pandemic has impacted the mental health of the general public, health care workers, and other frontline workers. To assess the pandemic’s mental health effects on public health workers, researchers from the CDC and colleagues collected data through an anonymous online survey conducted March 29-April 16, 2021. According to the results, 53% of 26,174 respondents employed by state, tribal, local, and territorial public health departments reported having at least one mental health symptom of depression, anxiety, post-traumatic stress disorder (PTSD), or suicidal ideation in the 2 weeks prior to completing the survey. The highest prevalences were reported among younger respondents, and transgender or nonbinary respondents, and the severity of symptoms increased as the proportion of time spent on COVID-19-related activities and time spent at work increased. Among respondents, the prevalence of reported PTSD symptoms were 10-20% higher than previously reported among healthcare workers, frontline workers, and the general public.
Equally alarming is the impact on the mental health of Americans of all ages. Emergency departments are witnessing an increasing proportion of patients with mental health crises, with more people visiting emergency rooms seeking help for overdoses and suicide attempts. These increases in adverse mental health symptoms are taxing already stressed healthcare systems, placing further pressure on frontline workers, and causing increased absenteeism, high turnover, lower productivity, and lower morale. Some experts warn that the true mental health impacts of the pandemic might not be known for years.
WHO MASKING GUIDANCE The WHO recently urged people fully vaccinated for SARS-CoV-2 to continue to wear masks in public, physically distance, and practice other COVID-19 prevention strategies in light of the rapidly spreading Delta variant of concern (B.1.617.2; VOC). The Delta variant, which has been identified in as many as 85 countries, is highly infectious and may be more likely to cause severe disease when compared with other SARS-CoV-2 variants. WHO Senior Advisor Dr. Bruce Aylward encouraged people who are vaccinated to continue to take precautions to avoid becoming part of a transmission chain. Even in countries with relatively high vaccination rates, including the UK and Israel, the Delta variant is causing an uptick in cases.
In the US, Delta variant prevalence has doubled over the last 2 weeks, and the variant is estimated to be responsible for 1 in 5 COVID-19 cases. US President Joe Biden on June 24 called the VOC a “serious concern,” warning those Americans who are not yet vaccinated are most at risk. The US CDC in May told fully vaccinated Americans they no longer need to wear masks indoors or physically distance themselves from other vaccinated individuals, and a CDC spokesperson gave no indication the current guidance will change. Some health experts encouraged US communities to tailor their masking guidance based on local vaccination and infection rates. However, various local recommendations could add confusion for some Americans who already cite questions over national guidance.
But with no way to verify whether people have been vaccinated, making it safer for them to unmask, some health experts are calling on the US government to do more to encourage and promote the use of SARS-CoV-2 vaccine mandates and passports. So far, the White House has largely avoided the topics, saying private companies should decide whether to implement passport requirements or mandates. Recently, at least 153 employees of Houston Methodist were terminated or resigned after a federal judge dismissed a lawsuit brought by workers of the health system, one of the first in the nation to impose a vaccine mandate. Many Republican governors have banned mandates or passports in their states, saying that vaccination is a personal choice. Some employers may be waiting for SARS-CoV-2 vaccines to receive full US FDA approval before implementing vaccination mandates. Both Pfizer-BioNTech and Moderna have applied for full approval, and the FDA is expected to make decisions later this summer or in early fall.
VACCINATING US HOMELESS POPULATIONS Although vaccinating persons experiencing homelessness is challenging in terms of outreach and education, about half of US states prioritize people living in homeless shelters in their vaccination plans, according to the Kaiser Family Foundation. Persons experiencing homelessness are less likely to seek medical care and lack access to adequate transportation, information, and personal protective equipment, placing them at greater risk of adverse health outcomes, including for COVID-19. The US Department of Housing and Urban Development estimates that 580,000 people were homeless during its January 2020 point-in-time survey.
In Nashville, Tennessee, the city’s Metro Public Health Department collaborated with local organizations and partners to improve access to SARS-CoV-2 vaccination for all persons experiencing homelessness through community-based events and outreach. According to Metro Health, the city has vaccinated at least 60% of its population experiencing homelessness, higher than the rate among the general public. Similarly, non-profit groups and partner organizations in Phoenix, Arizona, are coordinating vaccination drives and establishing mobile clinics in an effort to meet people where they are.
EUA FOR ACTEMRA The US FDA last week issued Emergency Use Authorization (EUA) for Roche’s Actemra/RoActemra (tocilizumab), already approved to treat moderate-to-severe rheumatoid arthritis. While healthcare providers have been offering the intravenous Interleukin-6 (IL-6) receptor antagonist to hospitalized COVID-19 patients on a compassionate care basis, the EUA will help expand the drug’s use to more patients who might benefit. Under the EUA, Actemra/RoActemra can be used in hospitalized adults and children (2 years of age and older) who are receiving systemic corticosteroids and require supplemental oxygen, non-invasive or invasive mechanical ventilation, or extracorporeal membrane oxygenation. In clinical trials, Actemra/RoActemra, in conjunction with corticosteroid treatment, reduced the risk of death through 28 days of follow-up, shortened the length of hospital stays, and reduced the need for mechanical ventilation. The FDA’s decision was informed by 4 clinical trials, particularly data from the RECOVERY and EMPACTA trials. Though Actemra/RoActemra is not authorized for outpatient use, the EUA adds another treatment to healthcare providers' toolkits to treat hospitalized COVID-19 patients.
AUSTRALIA The rapid global spread of the Delta variant of concern (B.1.617.2; VOC) has prompted renewed calls for lockdowns and other public health measures in countries worldwide. In Australia, which has had relative success in controlling the spread of SARS-CoV-2 within its borders, several major cities have reimposed lockdowns in response to a spike in COVID-19 cases caused by the Delta variant. These outbreaks have renewed questions over the dangers posed by strict hotel quarantines, which are the source of most community-spread cases, and the nation’s stuttering vaccination campaign, which has reached only 4.8% of adults, one of the lowest vaccination rates among high-income countries. Australia Prime Minister Scott Morrison met with state and territory leaders this week, agreeing to new measures to keep ahead of the Delta variant’s spread, as well as a no-fault indemnity plan for doctors administering SARS-CoV-2 vaccines. That plan effectively allows anyone under age 40 to receive the AstraZeneca-Oxford vaccine if they ask for it. Currently, the AstraZeneca-Oxford vaccine is recommended only for Australians over age 60 due to an increased risk of blood clots in younger individuals. That guidance has placed additional pressure on supplies of the Pfizer-BioNTech vaccine, which must be imported and is the only vaccine available for younger adults. Officials hope a return to stricter public health measures and a widening of vaccine access will help to control outbreaks as they arise.
OLYMPICS With less than 1 month before the 2020 Summer Olympic Games Opening Ceremony in Tokyo, a rise in daily COVID-19 cases in the country is prompting fears of another wave of infections and concerns over how Olympic organizers and Japanese authorities plan to host a safe event. This week, border control measures were put under a spotlight after an Ugandan Olympic team member tested positive for SARS-CoV-2 on June 26 upon arrival at the airport. While the team member was quarantined, officials allowed the rest of the team to proceed to the training center, where a second team member tested positive. Both team members tested positive for the Delta variant of SARS-CoV-2 (B.1.617.2), raising alarms over the variant’s increased transmissibility. On June 28, Japanese Prime Minister Yoshihide Suga pledged to strengthen border health controls in advance of more Olympic teams’ arrivals, but some health officials said the cases highlight how easily the controls can be breached. The government also has stepped up vaccination efforts, with the country last week administering more than 1 million doses a day. Still, only 11% of the population is fully vaccinated, and some wonder whether the accelerated pace will be enough to make a difference before the Olympic Games begin.
A recent poll showed that about 86% of those surveyed are concerned there will be an increase in COVID-19 cases following the Olympics, which are set to begin on July 23. Given the ongoing spread of the Delta variant and growing concern among the Japanese population, Japanese Emperor Naruhito gave a rare and unexpected remark of concerns over Japan hosting the Olympics. Though Emperor Naruhito does hold political power to stop the Olympics from proceeding, he is widely respected in Japan, and his comments put extra scrutiny on Olympics organizers to take as much care as possible.
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