On February 18, the U.S. reached 252.5 million persons (76.1% of the total U.S. population) having received at least one dose of a COVID-19 vaccine and 214.5 million persons (64.6% 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 (84.5%), Puerto Rico (83.9%), Vermont (83.8%), Connecticut (81.6%), and Massachusetts (81.5%). States with the lowest include Alabama (53.2%), Wyoming (53.6%), Mississippi (54%), Louisiana (56%), and Idaho (56.5%).
Also as of February 18, nearly 92.4 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 43.1% of those who are fully vaccinated, including 44.5% of those aged 12 years and older, 46.4% of those aged 18 years and older, and 65.7% 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 is consensus that Omicron is the most transmissible variant yet. According to the Centers for Disease Control & Prevention (CDC), Omicron is now the dominant strain in the United States. Omicron’s increased transmissibility may be due to how much more effectively it replicates in the upper respiratory tract. There are two strains of Omicron circulating in the U.S.: B.1.1.529 or BA.1 (i.e., the original Omicron strain) (96%) and BA.2 (i.e., a sub-lineage or “sister strain” of BA.1) (3.9%). Early data suggests that BA.2 is even more transmissible than BA.1. Another sub-lineage of Omicron, BA.3, has not yet been detected in the U.S.
The Omicron surge has posed significant challenges in the U.S. and globally. Even though CDC has determined that it is less virulent or causes less severe disease than previous variants, Omicron’s 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. Although adults hospitalized during the Omicron period overall were less likely to be admitted to intensive care units (ICUs) or require invasive mechanical ventilation (IMV) as compared to those admitted during the Delta surge, the CDC suggests this may be due to increases in the numbers of people who are vaccinated and/or boosted who are therefore at lower risk of severe disease. Recent 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 Delta. Boosters administered to immunocompromised and non-immunocompromised individuals strengthen antibody responses, although there is evidence to suggest that this wanes over time.
The Omicron surge also has impacted the testing infrastructure both in terms of unmet demand and, to a lesser extent, tests’ effectiveness, particularly rapid antigen tests. Some evidence suggests that rapid antigen tests, which use nasal swabs, may be less accurate at detecting Omicron in part since it is first detectable in a person’s throat before moving to their nasal passage. However, the CDC continues to recommend that nasal swab antigen tests only be used as authorized and not to swab the back of the throat. This is likely because it can be difficult or risky to self-administer an oral swab test.
Omicron has also shifted the treatment landscape for COVID-19. 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 treatments (e.g., sotrovimab, Evusheld), two antiviral oral medications (i.e., nirmatrelvir tablets/ritonavir tablets (Paxlovid), molnupravir), and one intravenous treatment (i.e., remdesivir (Velkury).
Although cases continue to drop each day in most areas of the U.S., it is impossible to definitively predict what will come next following this current Omicron wave. Some public health experts believe that Omicron will infect and therefore provide infection-induced immunity for enough of the population to protect against future variants. Others predict that any lull in infections could be temporary either because another more virulent and/or transmissible variant could arise or because protection from prior infections and/or vaccines could wane. As local jurisdictions and states increasingly relax COVID-related mandates and guidance, the CDC continues to emphasize the need for indoor masking in the majority of the U.S. In the weeks ahead, federal, state, and local guidance will likely continue to evolve as the current Omicron surge wanes.
On February 17, the CDC updated the vaccine guidance for immunocompromised individuals, allowing for a fourth shot at least three months after their third shot (changed from five months). The CDC wanted to update and reemphasize the need for a fourth shot for these individuals’ following reports that some are being turned away by pharmacies due to a lack of understanding of the current guidance. The following table summarizes when and what kind of booster different individuals are now eligible for:
|Primary Vaccine Series||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
|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 *
|Pfizer/BioNTech||Those 12 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 *
* 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 receiving a third Moderna shot, it should be a full-sized dose. At least three months after their third shot, moderately or severely immunocompromised individuals may receive a fourth mRNA dose.
** 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.
While the CDC has not yet altered their definition of “fully-vaccinated,” they have shifted their guidance by recommending that individuals “stay up to date” on their COVID-19 vaccines by receiving recommended boosters. Scientists and public health officials continue to analyze and release real-world data regarding the safety and the short- and long-term efficacy of the vaccine boosters, including against the Omicron variant. A surveillance report by CDC reinforced trial data that showed that homologous boosters (i.e., a third dose of the same mRNA vaccine as in the primary series) caused local and systemic reactions less frequently and less severely than second doses. Of note, myocarditis cases were extremely rare among those who received boosters and less frequent than observed after the second dose. The CDC has also released data on the waning efficacy of second and third doses of mRNA vaccines against emergency department (ED) visits and hospitalization. During the Omicron wave, vaccine effectiveness or protectiveness against ED visits dropped from 87% two months after a third dose to 66% by the fourth month. The pattern for effectiveness against hospitalization was similar, dropping from 91% two months after a third dose to 78% by the fourth month.
Meanwhile, Pfizer/BioNTech and Moderna have both announced plans to study the effectiveness of Omicron-specific vaccines. Pfizer/BioNTech has stated that an Omicron vaccine would be ready by March 2022. Moderna, meanwhile, is preparing its own Omicron vaccine for fall 2022. Yet early animal-based studies suggest that an Omicron-specific booster may not offer better protection than the original vaccine.
COVID-19 Vaccines for Children
The pediatric vaccine roll-out was considered fully up and running as of Monday, November 8. As of the end of January, 33% of children 5 – 11 years old are estimated to have received one or more vaccine doses, up from 16% in November. For comparison, 61% of parents of adolescents aged 12 – 17 years say that their child has received at least one dose. Regarding boosters, 21% of parents of teens say their child has already received a booster as 65% say will “definitely” or “probably” get one.
The Food and Drug Administration (FDA) and CDC have continued to closely monitor children who have received the Pfizer/BioNTech vaccine. The CDC has released data on the safety of the vaccines among children 5 – 11 years of age which demonstrate that they are incredibly safe with very few serious adverse events reported in this age group. In terms of efficacy, the vaccine is reported to have 92% efficacy against COVID-19 positive cases among adolescents based on real-world data. While additional real-world efficacy data will eventually be available for children 5 – 11 years of age, it is anticipated that the vaccine will remain protective particularly against severe disease. Booster shots for these children will also be considered by the FDA and CDC at some point in the coming weeks. Already, third shots are authorized for children aged 5 – 11 years of age with moderate or severe immunocompromise.
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.
Pfizer/BioNTech is using an “immune-bridging” approach by comparing antibody responses among children aged 6 months to 4 years who are participating in the trial to that seen in individuals aged 16 to 25 years of age. 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. Pfizer/BioNTech and FDA considered moving forward with the authorization process for the first two doses to allow parents to start the vaccination process amid the Omicron surge while awaiting data on the third dose. However, this approach raised questions among public health experts, including those concerned about potential vaccine hesitancy among parents of young children. Based on polling data from the Kaiser Family Foundation (KFF), 31% of parents of children 5 years and younger say they’ll get their child vaccinated against COVID-19 as soon as it is authorized while 29% say they will wait and see. Four out of ten parents said they would never get their child vaccinated or only if it is required. These trends are largely consistent with those observed among parents of children 5 – 11 years old.
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 changes to the definitions of “fully vaccinated” to include a booster dose and impacts that may have on vaccine requirements.
- Potential grant by FDA of an Emergency Use Authorization (EUA) for Pfizer/BioNTech vaccine for children under 5 years of age. Also, updated authorization for Moderna’s and Johnson & Johnson’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 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.