Booster may be needed before the holidays

Additional vaccines could be required to protect against virus, scientists say

More than 28 percent of Texans 16 and older are now fully vaccinated against COVID-19, having received either one shot of the Johnson & Johnson or two of Moderna or Pfizer.

But as scientists continue to study the virus and emerging variants, they’re concluding that even the fully vaccinated may need booster shots to stay protected.

“It might be necessary because of waning immunity,” said Dr. Wesley Long, an infectious disease expert at Houston Methodist Hospital.

“It might be necessary if we have a variant strain of COVID that maybe the original vaccines don’t protect against as well.”

So far, it’s looking probable people will require a booster shot around the holiday season. But there are still many unknowns.

Although the coronavirus pandemic has ravaged the globe for a year now, clinical trials for the vaccine haven’t been around as long. The most recent data from vaccine manufacturers show that the shots offer at least six months of protection, but researchers won’t know until the end of the year whether immunity lasts a full 12 months.

Dr. Anthony Fauci, head of the National Institute for Allergies and Infectious Diseases, said Thursday on MSNBC that most vaccine recipients should expect a booster shot in the next six to 12 months. Pfizer, Moderna and Johnson & Johnson are working on booster shots and expect annual revaccinations will be required.

Pfizer is running a booster shot trial based on emerging variants, said Pfizer spokesperson Kit Langley. The drug manufacturer recently confirmed its COVID-19 vaccine offers protection for at least six months. Moderna reported similar results from its study.

“We will continue to monitor participants in the trial for up to two years after their second dose to assess continued safety, efficacy and durability,” Langley said.

To test whether patients have lost protection, public health agencies and vaccine manufacturers will likely keep a close eye on

the rate of hospitalizations and deaths. If people lose immunity, it’ll likely taper off gradually rather than come to an abrupt end.

“One of two things can happen: We may lose protection against all COVID-19 symptoms, the mild and the severe, which would be a problem, right?” said Dr. Hana El Sahly, an associate professor of molecular virology and microbiology at Baylor College of Medicine. “Or it might be that we only lose protection against the mild symptoms, but retain protection against the severe symptoms.”

Like flu shots?

Researchers are still studying how SARS-CoV-2, the virus that causes COVID-19, is similar to other respiratory illnesses. While the disease has drawn some comparisons to influenza strains, the vaccines may work differently than flu shots, which require new vaccines every year to fend off emerging strains.

Even if the COVID-19 vaccine goes the way of the flu shot, experts say it’s not a bad sign.

“People shouldn’t be surprised, and it doesn't mean that the original vaccines are a failure at all,” Long said. The vaccine will still keep people from dying and help them avoid the hospital.

After six months, both Pfizer and Moderna show promising results in the remaining antibodies in their clinical trial participants, said Dr. PeiYong Shi, a professor of biochemistry and molecular biology at the University of Texas Medical Branch in Galveston. The Moderna clinical trial participants have been followed 209 days post-vaccination — that’s about six months, Shi said. Results show there was a “slight drop in antibodies” after six months in patients age 16 and older.

But Shi said “they still maintain active neutralizing antibody levels,” which is really good news.

“But what about up to 12 months?” he asks. “We don’t know because only time will tell.”

In addition to the predicted drop in efficacy, scientists also factor in a possible “breakthrough” — when the vaccine does not protect against a specific variant — when calculating the need for boosters.

When will it happen?

Scientists expect they’ll know for certain by the end of 2021 whether and when the public will need booster vaccines. Data on the effectiveness of the COVID-19 vaccines in the real world will become more available by December, the one-year anniversary of when health care workers began to receive Pfizer and Moderna vaccines.

Clinical trials such as Pfizer’s and Moderna’s will likely release efficacy data around that time.

And when the time comes, Texas will be ready, said Dr. David Lakey, a member of the Texas COVID-19 Expert Vaccine Allocation Panel.

The current vaccination system will be easy to adjust if Pfizer, Moderna or Johnson & Johnson data shows a stalling, or disappearing, efficacy rate, Lakey said.

“We’re concentrated on the primary vaccinations of individuals, but there is a system put in place that we can adjust accordingly if the data said we need to do that,” Lakey said.

Those who have already been vaccinated, such as travel agency owner Donna Daniels, accept that booster shots are part of their future. Daniels, who co-runs Fox Travel Agency in The Woodlands with her husband James Bailey, saw COVID-19 shots as part of the journey to traveling like normal again.

Although she does not require her clients to be vaccinated before booking vacation plans, many already have and are ready to get back on planes and cruise ships.

“If you made the decision to get the original vaccine, why wouldn’t you get a booster every year?” Daniels said.