NIH: COVID-19 booster-induced antibody response to omicron significantly decreases over time

As the World Health Organization reports a rise of COVID-19 infections globally, new research from the National Institutes of Health found that vaccine-induced immune response to the omicron variant driving these new waves diminished greatly over time. 

According to an NIH report published on July 19, NIH researchers found that while COVID-19 booster vaccinations create a strong antibody response against omicron initially, within three months post-boost, those levels decrease up to 5.3 fold. 

"Omicron sub-lineages BA.2.12.1 and BA.4/BA.5 were 1.5 and 2.5 times less susceptible to neutralization, respectively, compared to the BA.1 sub-lineage, and 7.5 and 12.4 times less susceptible relative to the ancestral D614G strain. BA.5 currently is the dominant variant in the U.S," NIH scientists said. 

The finding comes as WHO said 53 countries in its European region, which stretches to central Asia, reported nearly 3 million new coronavirus infections last week and that the virus was killing about 3,000 people every week. Globally, COVID-19 cases have increased for the past five weeks, even as countries have scaled back on testing.

In a statement on Tuesday, WHO's Europe director, Dr. Hans Kluge, described COVID-19 as "a nasty and potentially deadly illness" that people should not underestimate. He said super-infectious relatives of the omicron variant were driving new waves of disease across the continent and that repeat infections could potentially lead to long COVID.

Earlier this week, editors of two British medical journals said the country's National Health Service has never before had so many parts of the system so close to collapsing.

In the U.S. the Biden administration is calling on people to exercise renewed caution about COVID-19, emphasizing the importance of getting booster shots for those who are eligible and wearing masks indoors as two new highly transmissible variants are spreading rapidly across the country.

The BA.4 and BA.5 variants are offshoots of the omicron strain that has been been responsible for nearly all of the virus spread in the U.S. and are even more contagious than their predecessors. 

The BA.5 sub-strain now makes up more than 65% of U.S. cases, though scientists say it poses a lower risk for severe illness to those who are up to date on their vaccinations.

White House doctors stressed the importance of getting booster doses, even if you have recently been infected.

"Currently, many Americans are under-vaccinated, meaning they are not up to date on their COVID-19 vaccines," said Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention. "Staying up to date on your COVID-19 vaccines provides the best protection against severe outcomes."

Walensky said the U.S. has seen a doubling in the number of hospitalizations due to COVID-19 since April, reflecting the spread of the new subvariants, though deaths remain steady around 300 per day.

Despite the recent NIH findings, Dr. Anthony Fauci, the nation’s top infectious disease expert, with boosters, indoor masking and treatments the country has the tools to keep them from being disruptive, despite being a concerning new development in the war against COVID-19. 

On Thursday, President Joe Biden tested positive for COVID-19 and was placed in isolation with "very mild symptoms," the White House said.

Biden himself said in a video posted on Twitter: "I really appreciate your inquiries and concerns. But I’m doing well, getting a lot of work done."

Biden, 79, is fully vaccinated, after getting two doses of the Pfizer coronavirus vaccine shortly before taking office, a first booster shot in September and an additional dose March 30. The president will isolate for five days and can return to his usual activities after a negative test, White House COVID-19 coordinator Dr. Ashish Jha told reporters at a briefing.

After more than two years and over a million deaths in the U.S., the virus is still killing an average of 353 people a day here., according to the CDC. The unvaccinated are at far greater risk, more than twice as likely to test positive and nine times as likely to die from the virus as those who have received at least a primary dose of the vaccines, according to the public health agency.

The Associated Press contributed to this story. It was reported from Los Angeles.