On March 24, the U.S. reached 255.1 million persons (76.8% of the total U.S. population) having received at least one dose of a COVID-19 vaccine and 217.3 million persons (65.4% of the total U.S. population) being fully vaccinated (i.e., having received either one shot of the Johnson & Johnson/Janssen vaccine or two shots of either the mRNA Pfizer/BioNTech or Moderna vaccines). Jurisdictions with the highest percentages of persons 5 years of age and older being fully vaccinated include Rhode Island (85.8%), Puerto Rico (85.1%), Vermont (84.4%), Connecticut (82.5%), Hawaii (82.6%), and Maine (82.6%). States with the lowest include Alabama (53.8%), Wyoming (54.3%), Mississippi (54.8%), Louisiana (56.8%), and Idaho (57.2%).
Also as of March 24, nearly 97 million persons in the U.S. have received a booster (i.e., a third dose following an mRNA primary two-dose series or a second dose following a Johnson & Johnson/Janssen primary one-dose series). This represents 44.6% of those who are fully vaccinated, including 46.3% of those aged 12 years and older, 48.1% of those aged 18 years and older, and 67.1% of those 65 years and older. States with the highest rates of boosters administered among their fully vaccinated populations aged 12 years and older include Vermont (61%), Minnesota (58%), Wisconsin (55.8%), Maine (55.2%), Rhode Island (53%), and Iowa (52.9%).
The Impact of Variants
There are two strains of Omicron circulating in the U.S.: B.1.1.529 or BA.1 (i.e., the original Omicron strain) and BA.2 (i.e., a sub-lineage or “sister strain” of BA.1). The original Omicron strain, BA.1, was known as the most transmissible variant yet. Yet data suggests that BA.2 is roughly thirty-percent more transmissible than BA.1 and is now the most common COVID-19 strain in the U.S., representing more than half of all infections. Globally, the World Health Organization (WHO) has estimated that 85.9% of all cases are attributable to BA.2, with the variant driving surges in cases and hospitalizations in Southeast Asia and Western Europe. In the Northeastern U.S., cases have already started to increase though the extent to which BA.2 may cause another surge throughout the country remains unclear and difficult to determine. High rates of population-level immunity from vaccination and/or prior infection may prevent another major spike at least in some regions. On the other hand, the U.S. trails many Western countries in the proportion of people having received a booster dose.
The U.S. may also be challenged in detecting any possible surges in the months ahead. Many cities and states are closing community and/or health department-run COVID testing sites in response to decreased demand and uncertain funding. Throughout the Delta and BA.1 surges, at-home COVID antigen tests have increasingly been used as they have become more readily available. While more convenient and with far faster turnaround times than polymerase chain reaction (PCR) testing, at-home testing results are typically not reported to and captured by public health surveillance systems. As a result, federal, state, and local health officials have a harder time detecting and responding in a timely fashion to uptick in cases.
While several of the previously used monoclonal antibody treatments do not work against Omicron, other treatment options remain effective, albeit in limited supply or with greater difficulty of administration. These include the remaining effective monoclonal antibody treatment (e.g., Evusheld), two antiviral oral medications (i.e., nirmatrelvir tablets/ritonavir tablets (Paxlovid), molnupravir), and one intravenous treatment (remdesivir (Velkury). Of note, the Food & Drug Administration (FDA) no longer endorses use of the monoclonal antibody treatment sotrovimab as a treatment in areas of the U.S. where BA.2 is predominant as it is unlikely to be effective against the variant.
Although Centers for Disease Control & Prevention (CDC) has determined that both Omicron strains are less virulent or cause less severe disease than previous variants, their extreme transmissibility has caused hospital systems to be inundated with large influxes of patients and/or be short on staff as they too become sick. Studies indicate that current COVID-19 vaccines remain effective against Omicron including the BA.2 strain, particularly against severe disease, hospitalization, and death, although slightly less so than against the Delta variant. First boosters administered to immunocompromised and non-immunocompromised individuals strengthen antibody responses. However, there is evidence to suggest that this wanes over time. This evidence, and data from Israel regarding their own booster campaign, led the FDA and CDC to authorize second mRNA boosters for all persons 50 years of age and older and expand booster recommendations among other key groups.
Boosters
On March 15, Pfizer/BioNTech submitted for an updated emergency use authorization (EUA) allowing for a second booster for persons aged 65 years and older. Moderna followed on March 18 with their own submission allowing for a second booster for all adults aged 18 years and older. On March 29, the CDC updated their vaccine guidance, allowing, but declining to strongly recommend, adults aged 50 years and older receive a second mRNA booster. The CDC did recommend that moderately or severely immunocompromised individuals receive a second booster or fifth shot (i.e., three-shot primary series plus two boosters). Lastly, the CDC updated guidance for those who received an initial dose and a booster of the Johnson & Johnson/Janssen vaccine, recommending that they receive an mRNA shot at least four months after their booster. The FDA and CDC’s authorization was given in response to data regarding the waning vaccine efficacy against severe disease among older and/or immunocompromised individuals. The following table summarizes when and what kind of booster different individuals are now eligible for:
First Booster | Second Booster | |||||
---|---|---|---|---|---|---|
Primary Vaccine Series | Groups Eligible to Receive Booster | When to Receive Booster | Booster Doses Can Receive | Groups Eligible to Receive Booster | When to Receive Booster | Booster Doses Can Receive |
Johnson & Johnson / Janssen | Those 18 years and older | At least two months after first dose | •1 dose Johnson & Johnson/Janssen •1 full dose of Pfizer / BioNTech •1 half dose of Moderna | •Those age 18 years and older who received Johnson & Johnson / Janssen as first booster dose •Those age 50 years and older | At least four months after first booster | •1 full dose of Pfizer / BioNTech •1 half dose of Moderna |
Moderna | Those 18 years and older | At least five months after second dose * | •1 dose Johnson & Johnson/Janssen •1 full dose of Pfizer/BioNTech •1 half dose of Moderna * | •Those 50 years and older | At least four months after first booster | •1 full dose of Pfizer / BioNTech •1 half dose of Moderna * |
Pfizer / BioNTech | Those 5 years and older | At least five months after second dose * | •1 dose Johnson & Johnson/Janssen •1 full dose of Pfizer/BioNTech ** •1 half dose of Moderna * | •Those 50 years and older | At least four months after first booster | •1 full dose of Pfizer / BioNTech •1 half dose of Moderna * |
* Immunocompromised individuals aged 5 years of age and older (the vast majority of whom received a two-dose primary mRNA series) are recommended to receive a third mRNA vaccine dose 28 days after their second shot. If they are 18 years and older and receiving a third Moderna shot, it should be a full-sized dose. Moderately or severely immunocompromised individuals may receive a fourth mRNA dose at least three months after their third shot and a fifth dose at least four months after their fourth shot.
** Adolescents aged 12 – 17 years of age can only receive a third dose of the Pfizer/BioNTech vaccine as a booster. To date, the Pfizer/BioNTech vaccine is the only one to be authorized for this age group as either a primary series or booster.
Should additional boosters be recommended for all Americans eventually, Biden Administration and state/local health officials have reported that funding available to support the purchase and distribution of boosters will soon run out. Ongoing negotiations with Congress continue separately from an overall government spending package passed earlier this month. An analysis by the Kaiser Family Foundation estimates that the federal government does not have enough vaccine doses remaining in its current supply to fully cover the U.S. population under any of the following scenarios: (1) providing a fourth dose to those ages 50 years and older (consistent with current CDC-defined eligibility); (2) providing a fourth dose to those 65 years and older; (3) providing a fourth dose to those 18 years and older; or (4) providing a fourth dose to all ages. Even if the CDC and FDA guidance does not expand to other age groups, the U.S. government would only have 70% of the doses needed for persons aged 50 years and older.
COVID-19 Vaccines for Children
As of the end of February, 35% of children 5 – 11 years old are estimated to have received one or more vaccine doses, up from 33% in January. The share of parents who report that they will “definitely not” get their 5 – 11-year-old vaccinated increased from 24% in January to 36% in February. Meanwhile, 57% of parents of adolescents aged 12 – 17 years say that their child has received at least one dose. Regarding boosters, 31% of parents of teens say their child has already received a booster and 54% say that they will “definitely” or “probably” get one. Twenty-one percent of parents of teens said their child had received a booster as of the end of January.
For the youngest children (i.e., those aged 6 months to 4 years), vaccines will not be authorized and available until later this spring. Just before the FDA vaccine advisory body was scheduled to meet in mid-February to consider authorizing two 10 microgram doses of the Pfizer/BioNTech vaccine for this age group, the manufacturer announced that they would delay their application until data on the safety and efficacy of a third dose was available. In initial trial data, the two doses generated comparable antibody responses among children 6 months to 2 years but not among those aged 2 to 4 years. As of the end of March, Pfizer/BioNTech has not yet released updated trial data regarding the efficacy of a third dose in this age group but is anticipated to do so in April.
Meanwhile, Moderna has asked the FDA to authorize their own two-dose COVID vaccine for children 6 months to 6 years. On March 23, the manufacturer released data detailing how its vaccine generated comparable antibody responses in younger children as seen in adults. The shots, at one quarter the size of adult doses, were less effective in preventing symptomatic infections than seen in previous trials in older groups. In children 6 months to 23 months, cases of COVID were decreased by 43.7%. Among those aged 2 – 6 years of age, the decrease was 37.5%. Moderna has said that this lower efficacy against symptomatic disease is to be expected against the Omicron variant. Moderna will continue to study third booster doses in these age groups. The company has also submitted a separate EUA for children ages 6 -11 and updated its EUA for teens aged 12 – 17 years of age. As of the end of March, the Moderna vaccine is only authorized for those 18 years of age and older.
Future Considerations
In the weeks ahead, members of the attorney general community should monitor and be aware of the following possible key events related to the vaccines’ rollout:
- Further updated guidance released by the CDC and state/local health departments regarding the need for non-medical interventions (e.g., mask wearing, social distancing) by fully vaccinated, boosted, and unvaccinated individuals generally and within specific settings.
- Potential grant by FDA of an EUA for Pfizer/BioNTech vaccine for children under 5 years of age. Also, updated authorization for Moderna’s vaccines for individuals under 18 years of age.
- Additional information on the (1) transmissibility, (2) disease severity, and (3) potential for immune escape of the Omicron variant and its sister variant, BA.2.
- The possible emergence of other variants with increased transmissibility, virulence, and/or immune escape.
- Release of additional data regarding the safety and efficacy of mixing and matching vaccines for purposes of boosters.
- Additional changes to the vaccine distribution, testing, and treatment landscape for COVID in the U.S. in the absence of additional funding appropriated by Congress.
- Additional vaccine manufacturers possibly seeking authorization in the U.S., including the two-dose AstraZeneca/Oxford University and Novavax
In 2022, NAAG will continue to provide informational updates and training opportunities to the attorney general community as COVID-19 vaccine distribution and related legal issues evolve. For more information on NAAG’s response to the COVID-19 pandemic, visit NAAG’s public health-related updates.