As delta variants spread, J & J shots may require boosters, and some experts have already adopted them.

Infectious disease experts say that Pfizer / BioNTech or Modern RNA-based vaccines are available for Americans who have received a Johnson & Johnson single-dose vaccine due to the increasing prevalence of more contagious deltacoronavirus variants. We are considering the need for booster shots.

Even without published data on whether combining two different vaccines is safe and effective, or with the support of U.S. health regulators, they already do so. Some people say that. Canada and some European countries have already allowed people to get two different COVID-19 shots.

At the heart of the debate is the concern about how well J & J shots are protected against the delta variants that were first detected in India and are now widely distributed in many countries. Delta is also associated with more serious illnesses and could soon become the predominant version of the virus in the United States, warned Rochelle Walensky, director of the Centers for Disease Control and Prevention (CDC). ..

There are no substantive data showing how defensive the J & J vaccine is against new variants. However, a UK study showed that two doses of either the Pfizer / BioNTech vaccine or the AstraZeneca vaccine were significantly more protective against the mutant than one dose.

Andy Slavit, a former senior pandemic adviser to President Joe Biden, raised the idea in his podcast this week. At least half a dozen prominent infectious disease experts said US regulators need to address this issue in a short period of time.

“There is no doubt that people who get the J & J vaccine have less protection from the disease than people who get two other injections,” said Michael Lin, a professor at Stanford University. “This is not really easy because of the principle of taking simple steps to prevent really bad results.”

The CDC has not recommended boosters, and official advisers said at a public meeting this week that there is still no significant evidence of reduced protection from vaccines.

Jason Gallagher, an infectious disease expert at Temple University’s Pharmacy University, recently received Pfizer at the Philadelphia Vaccine Clinic where he is taking shots. He was vaccinated with the J & J vaccine in a clinical trial in November.

Gallagher said he was worried UK data It has shown lower efficacy against delta variants in single-vaccinated people.

“The situation is much better in the United States, but the rapidly prevailing variant of Delta in the United States seems to be a little more concerned about breakthrough infections with single-dose vaccines,” he said. “That’s why I took the plunge.”

In the United States, cases, hospitalizations and deaths have plummeted and 56% of the adult population is fully vaccinated.

J & J said it is testing whether the immune response from the vaccine can neutralize the delta mutant in a laboratory setting, but data are not yet available.

Both mRNA vaccines showed an efficacy rate of about 95% in a large US study, while the J & J vaccine was moderate to severe when more infectious mutants were circulating. It was 66% effective in preventing COVID-19.

Dr. Angela Rasmusen, a researcher at the University of Saskatchewan’s Vaccine and Infectious Diseases Organization, said on Twitter that she had been vaccinated with Pfizer this week after receiving a J & J in April.

Rasmussen, who refused to interview, recommended that Americans vaccinated with the J & J vaccine consult their doctors about possible second shots.

“If you live in an area that is generally low in vaccination, we strongly recommend that you consider doing so,” she tweeted.

Dr. Peter Hotez, a vaccine expert at Baylor College of Medicine, said in a tweet that adding a second J & J dose or one of the mRNA vaccines could provide broader protection.

The National Institute of Allergy and Infectious Diseases (NIAID) is conducting a study to determine the need for boosting all currently permitted shots with different doses of the modelna vaccine. NIAID scientist Dr. John Beiger told Reuters that he hopes to have the data available by September to inform regulators of booster decisions.

He said J & J recipients should wait for more data as long as the number of cases remains low in the United States.

If there was a significant increase in infections and hospitalizations due to the delta mutation, he said: But for now, I think it’s appropriate for them to wait. “