COVID-19 Weekly Newsletter: Additional Booster Shots Recommended as FDA Prepares to Evaluate Vaccines for Younger Children

Booster Shot Endorsements

Last week, the U.S. Food and Drug Administration (FDA) advisory committee endorsed one of the mRNA COVID-19 vaccines and the single-dose vaccine to be used as a booster shot. This week, FDA endorsed the advisory committee’s recommendations, the Centers for Disease Control and Prevention’s (CDC) Advisory Committee on Immunization Practices (ACIP) recommended the same and CDC Director Rochelle Walensky endorsed ACIP’s recommendation. The mRNA booster was recommended for older adults and at-risk adults six months after they complete their primary series of shots. The single-dose booster was endorsed for everyone 18 and older who received the initial shot at least two months ago.

Shots for Children

On October 26, 2021, FDA will evaluate the emergency use authorization (EUA) of one of the mRNA vaccines to be able to be administered to children ages 5 to 11. On October 22, 2021, the manufacturer released its phase three clinical trial data showing its vaccine has 90.7% efficacy against preventing symptomatic infections from SARS-CoV-2.

“Delta Plus”

A subtype of the Delta variant of COVID-19 is starting to raise concern with scientists. Known as AY.4.2 and unofficially called “Delta Plus,” this variant has two mutations in the spike protein, which is the protein used by the virus to enter cells. Data suggests that Delta Plus could be 10% more infectious than Delta. Recently, there has been an uptick in cases in the United Kingdom, accounting for 6% of COVID-19 cases. Delta Plus has also been observed in the U.S. but not in clustered or increased frequency to suggest it is taking hold. 

There Is No Test for Immunity Against COVID-19

There are a number of tests that can tell whether a person was recently infected with COVID-19, but there are currently no tests that can confirm whether a person has immunity. For example, antibody tests can measure the levels of antibodies circulating in the blood, but there is no established “translation” of those levels to the actual immunity. How much, and what types, of antibodies are needed to protect a person against infection if exposed to a virus (and “how much” of a virus)? How does that “protective” level depend on the person’s characteristics, such as age, gender and concurrent medical conditions? And since the antibody test results depend on a particular test employed, what should be the standard test to measure antibodies? These questions have no answers at the moment. Furthermore, immunity comes not only from antibodies circulating in the blood (which get generated in response to an infection or vaccination and then disappear), but also from T-cells, memory B-cells and other components of the immune system acting “centrally”/systemically and “locally”/in specific tissues. Future research may bring clarity to the question of immunity. 

Portable HEPA Filters

Further evidence was published that even portable versions of air purification systems with HEPA filters help clear the air of SARS-CoV-2 virus particles.

Vaccination During Pregnancy Is Safe

Another study appeared to add to the previously published evidence that vaccination against COVID-19 is safe during pregnancy. Safety of the COVID-19 vaccines is continuously monitored for mRNA and other vaccines authorized in the U.S.

New Insight Into COVID-19 Breakthrough Infections

Further to our coverage of ongoing research on correlates of protection for SARS CoV-2, a recent study has examined breakthrough infections in vaccinated health care workers at a large hospital. The percentage of breakthrough infections was very low, and among these cases, individuals were asymptomatic or showed only mild symptoms. Importantly for this study, researchers found that low levels of antibodies, compared to controls, were found in individuals with breakthrough infections. Specifically, the study found that neutralizing antibody levels seen during the week prior to SARS CoV-2 detection correlates with infectivity (viral loads) of breakthrough cases. This finding is important since studies suggest that vaccine immunity is protective against disease but a bit less protective against infection and infectivity. Also, importantly, no secondary infections were traced to any of the breakthrough cases, which supports other evidence that the vaccinated are less contagious than unvaccinated individuals.

Additional Resources

Information regarding the status of each foreign patent office and the availability of extensions of time in each jurisdiction.

Tracking executive orders, legislation, and other government actions related to COVID-19 by state and major locality across the U.S.