Antibodies against coronavirus detectable up to seven months post COVID-19 onset, says study

Agencies
October 24, 2020

Antibodies against the novel coronavirus follow a classic pattern with a rapid increase within the first three weeks after symptoms, and detectable up to seven months post contracting the disease, according to a new study which assessed 300 patients infected with the virus and 198 post-COVID-19 volunteers.

According to the research, published in the European Journal of Immunology, the participants had antibodies with confirmed neutralisation activity for up to six months post infection with the SARS-CoV-2 virus.

The scientists, led by Marc Veldhoen from Instituto de Medicina Molecular (IMM) in Portugal, monitored the antibody levels of over 300 COVID-19 hospital patients and healthcare workers, 2500 university staff, and 198 post-COVID volunteers.

They setup an in-house sensitive specific and versatile COVID-19 serology test.

The study revealed that 90 per cent of subjects have detectable antibodies up to seven months post contracting COVID-19.

It also found that age was not a confounding factor in levels of antibodies produced, but disease severity is.

"Our immune system recognises the virus SARS-CoV-2 as harmful and produces antibodies in response to it, which helps to fight the virus," Voldhoen said.

"The results of this six months cross-sectional study show a classic pattern with a rapid increase of antibody levels within the first three weeks after COVID-19 symptoms and, as expected, a reduction to intermediate levels thereafter," he added.

Based on the findings, the scientists said men produce more antibodies on average than women, "but levels equilibrate during the resolution phase and are similar between the sexes in the months after SARS-CoV-2 infection".

In the acute phase of the immune response, the researchers observed higher antibody levels in subjects with more severe disease.

They said age is not a confounding factor for the production of antibodies since no significant differences were observed between age groups.

While there was a reduction in the levels of antibodies over time, the team found that there was "robust neutralisation activity" for up to the seventh month post-infection in a large proportion of previously virus-positive screened subjects.

"Our work provides detailed information for the assays used, facilitating further and longitudinal analysis of protective immunity to SARS-CoV-2," Veldhoen said.

"Importantly, it highlights a continued level of circulating neutralising antibodies in most people with confirmed SARS-CoV-2," he added.

The researchers believe the next months will be critical to evaluate the robustness of the immune response to SARS-CoV-2 infection, and to find clues for questions such as the duration of circulating antibodies and the impact of reinfection.

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Agencies
November 25,2020

In view of the winter season and COVID-19, health experts on Wednesday said that many people are taking pneumonia and influenza vaccines as a precaution to save themselves from respiratory infections.

Experts have warned that it is highly possible that people may contract both influenza and the COVID-19 infection in winter, leading to devastating consequences.

Dr Avi Kumar, Consultant - Pulmonology, Fortis Escorts Heart Institute in New Delhi said, "What we are generally following is that in post COVID patients we are giving flu vaccine as well as the pneumonia vaccine."

"Because right now we are at the start of winter and this is generally the beginning of flu season as well as coronavirus. Both are RnA viruses so the vaccine which is available against influenza is known to be very helpful in reducing hospitalization," Kumar explained.

International researchers have recently found that receiving the influenza vaccine does not increase a person's risk of contracting COVID-19 or worsen associated morbidity or mortality.

Published in the Journal of Clinical and Translational Science, the study shows the flu vaccine is the single most important intervention to help in staying healthy this fall and winter.

"More studies need to be done to confirm the same, only a few studies cannot confirm it," Kumar said.

"However, what is available with us right now is prevention of other respiratory infections in the form of flu as well as pneumonia so that hospitals are not overburdened with other respiratory illnesses as well as Covid patients," he added.

"Hence, we prefer tetravalent inactivated flu vaccine which has been given to every patient in post Covid status.

"In addition we have been giving them vaccines for pneumonia, conjugate vaccine is been given to the age group of above 65 years, this vaccine is given only once in a lifetime. We are also giving a polyvalent vaccine which is to be repeated once in every five years," Kumar said.

According to Dr Akshay Budhraja, Consultant Department of Pulmonology, Aakash Healthcare Super Speciality Hospital, in the absence of a vaccine specific to the Covid-19 virus right now, they are checking the vaccination history of the patient.

"We give one shot of flu vaccine every year and pneumococcal vaccine is given once in five years. As of now, we have not faced any shortage," Budhraja told IANS.

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News Network
November 19,2020

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Researchers in Denmark reported on Wednesday that surgical masks did not protect the wearers against infection with the coronavirus in a large randomized clinical trial. But the findings conflict with those from a number of other studies, experts said, and is not likely to alter public health recommendations in the United States.

The study, published in the Annals of Internal Medicine, did not contradict growing evidence that masks can prevent transmission of the virus from wearer to others. But the conclusion is at odds with the view that masks also protect the wearers — a position endorsed just last week by the Centers for Disease Control and Prevention.

Critics were quick to note the study’s limitations, among them that the design depended heavily on participants reporting their own test results and behavior, at a time when both mask-wearing and infection were rare in Denmark.

Coronavirus infections are soaring throughout the United States, and even officials who had resisted mask mandates are reversing course. Roughly 40 states have implemented mask requirements of some sort, according to a database maintained by The New York Times.

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, advocates a national mask mandate, as does President-elect Joe Biden.

“I won’t be president until January 20th, but my message today to everyone is this: wear a mask,” Biden recently wrote on Twitter.

From early April to early June, researchers at the University of Copenhagen recruited 6,024 participants who had been tested beforehand to be sure they were not infected with the coronavirus.

Half were given surgical masks and told to wear them when leaving their homes; the others were told not to wear masks in public.

At that time, 2% of the Danish population was infected — a rate lower than that in many places in the United States and Europe today. Social distancing and frequent hand-washing were common, but masks were not.

About 4,860 participants completed the study. The researchers had hoped that masks would cut the infection rate by half among wearers. Instead, 42 people in the mask group, or 1.8%, got infected, compared with 53 in the unmasked group, or 2.1%. The difference was not statistically significant.

“Our study gives an indication of how much you gain from wearing a mask,” said Dr. Henning Bundgaard, lead author of the study and a cardiologist at the University of Copenhagen. “Not a lot.”

Dr. Mette Kalager, a professor of medical decision-making at the University of Oslo, found the research compelling. The study showed that “although there might be a symbolic effect,” she wrote in an email, “the effect of wearing a mask does not substantially reduce risk” for wearers.

Other experts were unconvinced. The incidence of infections in Denmark was lower than it is today in many places, meaning the effectiveness of masks for wearers may have been harder to detect, they noted.

Participants reported their own test results; mask use was not independently verified, and users may not have worn them correctly.

“There is absolutely no doubt that masks work as source control,” preventing people from infecting others, said Dr. Thomas Frieden, chief executive of Resolve to Save Lives, an advocacy group, and former director of the CDC, who wrote an editorial outlining weaknesses of the research.

“The question this study was designed to answer is: Do they work as personal protection?” The answer depends on what mask is used and what sort of exposure to the virus each person has, Frieden said, and the study was not designed to tease out those details.

“An N95 mask is better than a surgical mask,” Frieden said. “A surgical mask is better than most cloth masks. A cloth mask is better than nothing.”

The study’s conclusion flies in the face of other research suggesting that masks do protect the wearer. In its recent bulletin, the CDC cited a dozen studies finding that even cloth masks may help protect the wearer. Most of them were laboratory examinations of the particles blocked by materials of various types.

Susan Ellenberg, a biostatistician at the University of Pennsylvania Perelman School of Medicine, noted that protection conferred by masks on the wearer trended “in the direction of benefit” in the trial, even if the results were not statistically significant.

“Nothing in this study suggests to me that it is useless to wear a mask,” she said.

Dr. Elizabeth Halloran, a statistician at Fred Hutchinson Cancer Research Center in Seattle, said the usefulness of masks also depends on how much virus a person is exposed to.

“If you show this article to a health care provider who works in a COVID ward in a hospital, I doubt she or he would say that this article convinces them not to wear a mask,” she said.

But Dr. Christine Laine, editor in chief of the Annals of Internal Medicine, described the previous evidence that masks protect wearers as weak.

“These studies cannot differentiate between source control and personal protection of the mask wearer,” she said.

Laine said the new study underscored the need for adherence to other precautions, like social distancing. Masks “are not a magic bullet,” she said. “There are people who say, ‘I’m fine, I’m wearing a mask.’ They need to realize they are not invulnerable to infection.”

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Agencies
December 1,2020

Pune, Dec 1: Vaccine development company Serum Institute, India on Tuesday said the Covidshield vaccine will not be released for mass use unless it is proven immunogenic, and safe.

The company also said the serious adverse event (SAE) that happened to a city based volunteer though unfortunate was in no way induced by the vaccine.

Serum Institute which had earlier said it would claim over Rs 100 crore damage from the volunteer for damaging its reputation said it was sympathetic with the volunteer's medical condition and the incident is highly unfortunate.

"However, we would like to clarify that all the requisite regulatory and ethical processes and guidelines were followed diligently and strictly," the company said.

According to Serum Institute, the concerned authorities were informed and the Principal Investigator, Data Safety Monitoring Board (DSMB) and the Ethics Committee independently cleared and reckoned it as a non-related issue to the vaccine trial.

"Post which we submitted all the reports and data related to the incident to the DCGI (Drug Controller General of India). It is only after we cleared all the required processes that we continued with the trials," the company said.

"Taking into consideration the complexities and existing misnomers about vaccination and immunisation; the legal notice was sent therefore to safeguard the reputation of the company which is being unfairly maligned," the company added.

The 40-year-old city based volunteer, who works as a business consultant had wanted to investigate the cause of him contracting severe neurological health complications he had suffered after being vaccinated with Covidshield shots under development at Serum Institute, but the company was intimidating him with a threat of over Rs 100 crore damage suit, his advocates had said.

According to the advocates, their client was vaccinated on September 29 and developed severe neurological health complications and instead of probing the cause and stopping the trials Serum Institute and others kept silent.

"We are yet to get any reply for the legal notice sent to various parties, including Serum Institute. We have seen news reports about Serum Institute threatening our client with a suit for over Rs 100 crore," N.G.R. Prasad, Advocate, Row & Reddy, told IANS.

"Our client had restricted his claim only for Rs 5 crore and wanted investigation to start as to the cause of him suffering severe neurological problems and stop the vaccine from affecting other people," Prasad added.

A family friend of the volunteer told IANS: "He was a healthy young male. He had no pre-existing ailments. Not even blood pressure. But 10 days after the vaccination, he had developed severe neurological complications."

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