Today the US Food and Drug Administration (FDA) authorized a second booster shot for Americans over 50 and for those 12 years and older who are immunocompromised.
"Current evidence suggests some waning of protection over time against serious outcomes from COVID-19 in older and immunocompromised individuals. Based on an analysis of emerging data, a second booster dose of either the Pfizer-BioNTech or Moderna COVID-19 vaccine could help increase protection levels for these higher-risk individuals," said Peter Marks, MD, PhD, director of the FDA's Center for Biologics Evaluation and Research, in a press release.
The authorization is for the Pfizer and Moderna vaccines only, and both shots should be administered at least 4 months after the first booster dose.
The CDC COVID Data Tracker shows that 65.5% of Americans are fully vaccinated against COVID-19, 76.9% have received at least one dose of vaccine, and 44.8% of fully vaccinated Americans have received a booster dose.
It's unclear if the Omicron BA.2 subvariant now dominant in the United Kingdom—will cause a surge in new COVID-19 cases in the United States, but some experts believe Americans most at risk for severe COVID-19 outcomes should get a booster.
BA.2 now makes up more than half of sequenced samples in the United States, or 55%, up from 35% last week.
CDC green-lights boosters
Following the FDA's announcement, the Centers for Disease Control and Prevention (CDC) said it also now recommends that immunocompromised Americans and older adults get a second booster dose. The agency also encouraged adults who had received one or two Johnson & Johnson (J&J) doses to get an mRNA booster, as well.
"Today, CDC expanded eligibility for an additional booster dose for certain individuals who may be at higher risk of severe outcomes from COVID-19," CDC Director Rochelle Walensky, MD, MPH, said in a statement sent to the media. "CDC, in collaboration with FDA and our public health partners, will continue to evaluate the need for additional booster doses for all Americans."
Supporting the announcement was evidence published today in Morbidity and Mortality Weekly Report, which shows that adults first vaccinated with the J&J vaccine get better long-term protection with an mRNA booster.
The VISION Network study determined real-world vaccine efficacy (VE) of one J&J vaccine and two alternative booster dose strategies: Another J&J shot, or one mRNA booster dose. The study examined 80,287 emergency department/urgent care (ED/UC) visits, and 25,244 hospitalizations across 10 states during Dec 16, 2021, through Mar 7, 2022, which included the Omicron surge.
The VE against COVID-19–associated ED/UC visits was 24% after 1 J&J dose, 54% after 2 J&J doses, and 79% after 1 J&J/1 mRNA dose, compared with 83% after 3 mRNA doses, the authors said. VE for the same strategies against COVID-19–associated hospitalization was 31%, 67%, 78%, and 90%, respectively.
"These findings underscore the importance of receiving recommended COVID-19 booster doses, when eligible, to prevent moderate to severe COVID-19 during Omicron variant predominance. All adults who have received mRNA vaccines for their COVID-19 primary series vaccination should receive an mRNA booster dose when they are eligible," the authors said.
Deaths drop across US
Deaths from COVID-19 in the United States are now at their lowest rates since last August, with fewer than 800 deaths per day recorded. Average daily new cases have held at 30,000 per day, and hospitalizations stand at roughly 18,000 per day.
The United States reported 42,967 new COVID cases yesterday, plus 985 deaths, per the Johns Hopkins tracker.
China balances strong steps, economic fallout
In China, Shanghai's two-tiered lockdown entered its second day, as mass testing continues to turn up hundreds of asymptomatic infections. Of 6,886 local cases reported from China today, 5,658 were asymptomatic, about 77% of which were from Shanghai.
Businesses in Shanghai, one of the country's financial and manufacturing hubs, are scrambling to adapt to the lockdown requirements, such as General Motors, which is reportedly keeping production going by having employees sleep on factory floors, according to Reuters. In other instances, companies are keeping operations going by using a "bubble" approach, similar to the closed-loop method used during the Beijing Winter Olympics.
Elsewhere in China, most symptomatic cases continue to be reported from major cities in Jilin Province, where officials in the capital city Changchun apologized to citizens for pandemic-related food shortages, according to Reuters.
In other recent Asian hot spots, which experienced later Omicron surges, cases declined, such as Hong Kong, where daily cases were at their lowest in 5 weeks with 7,596 new cases reported today.
However, in South Korea, after a 5-day decline in cases, the daily total was up again, with 347,374 new cases today, with health officials noting that patterns may be unpredictable owing to the more transmissible BA.2 subvariant, which became the country's dominant strain last week, according to The Korea Herald.
CIDRAP News Editor Lisa Schnirring contributed to this story.