A nurse administers a booster vaccine at a Covid-19 vaccination clinic on April 0-6, 2022 in San Rafael, California.
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Covid vaccines, while strongly resistant to hospitalization and death, offer little protection against long Covid, according to research published Wednesday in the journal Nature Medicine.
The findings are disappointing, if not surprising, for researchers who previously hoped the vaccination could significantly reduce the risk of long-term Covid-19.
Compared to an unvaccinated person, the risk of Covid-19 in a fully vaccinated person was reduced by only 15 percent, the study found.
“Vaccines are miraculous in doing what they were designed to do, which is to prevent hospitalization and death,” said Dr. Ziyad Al-Aly, a clinical epidemiologist at Washington University in St. Louis. Louis and lead author of the study. But “they offer very modest protection against the long Covid,” he said.
Covid vaccines were developed at the beginning of the pandemic, long before doctors, scientists, and patients became aware of Covid’s long existence. They were never designed to protect against this, said Al-Aly, who is also the head of research at VA St. Louis Health Care System. “We need to review them now that we know that the virus can also have long-term consequences.”
Dr. Greg Vanichkachorn, director of the Covid Rehabilitation Program at Mayo Clinic in Rochester, Minnesota, who did not participate in the new study, said the results were not “too surprising.”
“We know that most people with long Covid have not had any serious infections,” he said.
The study looked at U.S. Department of Veterans Affairs national health care data and included medical records of about 34,000 people vaccinated who had innovative Covid infections and more than 113,000 who were not vaccinated when they left. become infected with Covid from January 2021 to October 2021. fully vaccinated if they had received two doses of the Pfizer-BioNTech or Moderna vaccine or a single dose of the Johnson & Johnson vaccine.
The researchers followed up six months after the infection to see if the patients had persistent symptoms. Although protection against long-term Covid was generally relatively small, vaccines were more effective in preventing some of the most life-threatening symptoms of long-term Covid: vaccination reduced the risk of lung disorders by nearly 50 percent. blood clotting disorders by 56 percent, by comparison. with those who were not vaccinated.
Al-Aly noted that an innovative case does not mean that one person will develop a long Covid, only 10% of innovative cases will lead to the disease, but with so many people infected, this still translates into a large number of people.
The data did not show whether a person was potentiated, but Al-Aly said he does not expect the increase to make a big difference in terms of vaccines that protect against long Covid, or variants like omicron.
Vanichkachorn agreed. “Unfortunately, I don’t think the increase will do much to prevent Covid with the vaccine for long,” he said. “We have a lot of patients with innovative infections who are as vaccinated as possible. We haven’t seen much difference between variants with long symptoms of Covid either.”
This is not to say that vaccines are not an important tool in the fight against the pandemic, experts say.
Reinforcements, in particular, provide maximum protection against severe acute Covid and reduce the risk of complications, said Dr. Jason Maley, director of the critical illness and COVID-19 survival program at Beth Israel Deaconess Medical Center in Boston.
But for a long time Covid, they are not necessarily the solution. “I don’t think vaccination is the key to eliminating long Covid,” Al-Aly said. “We really need to think of additional layers to protect ourselves from the long-term consequences of this virus.”
New approaches to prevent long Covid
Covid cases are on the rise again in the U.S., now driven by an omicron subvariant called BA.2.12.1, according to the Centers for Disease Control and Prevention. However, public health measures such as masking and social distancing have fallen sharply.
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Al-Aly said he does not blame people for this.
“It’s not pragmatic to tell people to mask themselves for the next 10 years,” he said. But it does emphasize the need to improve vaccines and treatments in a way that can provide protection against long Covid.
“Now that we’ve lifted all these other public health measures, vaccines are really the only layer of protection we have,” Al-Aly said. “This puts even more urgency on the question of what other preventions or treatments might be available. Can we modify these original vaccines to address long-term Covid as well, or do we also need intranasal vaccines or other therapies in addition?”
Intranasal vaccines, for example, may be better at preventing transmission than current vaccines, but this is an area that needs to be investigated, he said.
Maley, who also did not participate in the study, said growing research suggests that one of the major long-term risk factors for Covid is the level of virus in the body during acute infection. This suggests that early treatment with therapies that include antivirals may help prevent Covid for a long time by keeping these virus levels low.
“Right now, antivirals are approved for emergency use for patients who are at high risk for severe Covid-19, usually older adults or people with compromised immune systems,” Maley said. . There is also interest, he said, in studying whether antiviral treatments could benefit long-term Covid patients.
Both Al-Aly and Vanichkachorn agreed that more research on long Covid is needed. “We need continued research specifically on long Covid so that specific therapies can be developed,” Vanichkachorn said.
But right now, he said, “the best way not to have long Covid is to not have Covid.”