The immune response to COVID-19 helps protect against reinfection, but that protection is weaker against Omicron than it was against earlier variants of the coronavirus, according to new data. In other news, protection provided by booster shots of the mRNA vaccines from Moderna Inc. or Pfizer Inc. and partner BioNTech SE starts waning quickly, according to data published in Feb. 11th’s Morbidity and Mortality Weekly Report from the U.S. Centers for Disease Control and Prevention (CDC).

The World Health Organization indicated WHO is tracking four Omicron subvariants: BA.1, BA.1.1, BA.2 and BA.3. BA.2 has a growth advantage over BA.1, the variant responsible for the recent Omicron surge.

The latest wave of COVID-19 infections has “overwhelmed” Hong Kong, the city’s leader said on Feb. 14, as daily cases have surged by some 20 times over the past two weeks, leaving hospitals short of beds and struggling to cope. South Korea will begin giving out fourth doses of COVID-19 vaccines during February and supply millions of additional home test kits to ease shortages amid a surge in Omicron infections, authorities confirmed on Feb. 14.

Gilead Sciences Inc.’s antiviral drug remdesivir showed antiviral activity against Omicron, Delta and other variants of the coronavirus in laboratory studies, the company said on February 11.

An antibody-based COVID-19 therapy developed by GSK and Vir Biotechnology retains neutralizing activity against the emerging BA.2 form of the Omicron coronavirus variant, according to data from a laboratory study cited by Vir on February 10.

Jane Qiu, a freelance science writer based in Beijing, published an overview of her efforts to investigate the lab-leak theory for the origin of COVID-19. In another update, the FDA’s Vaccines and Related Biological Products Advisory Committee is scheduled to meet on February 15 to discuss an amended Emergency Use Authorization for the Pfizer-BioNTech COVID-19 vaccine for children 6 months through 4 years of age.

Global COVID-19 cases surpassed 400 million on February 9, according to a Reuters tally, as the highly contagious Omicron variant dominates the outbreak, pushing health systems in several countries to the brink of capacity.

New COVID-19 cases in Tokyo exceeded 20,000 for the first time on Feb. 2, dimming hopes that a wave of infections fueled by the Omicron variant is peaking in Japan.

Aside from vaccines, the advent of several effective COVID-19 antiviral therapies, including Pfizer’s Paxlovid, provides hope for ending the pandemic. Details about the U.S. government’s contract with Pfizer for 10 million doses of Paxlovid are emerging, with some unusual elements.

Many countries have not reached their peak in cases of the highly transmissible Omicron variant of the coronavirus and measures imposed to curb its spread should be eased slowly, the World Health Organization’s technical lead on COVID-19 said on Feb. 1.