Pfizer's Covid vaccine COULD stop people spreading the virus as well as preventing serious illness, Israeli doctor claims
Pfizer's Covid vaccine could produce a strong enough immune response to stop people who get the jab from spreading the coronavirus, a doctor in Israel has claimed.
Researchers found in a small study that recipients of the jab developed up to 20 times more antibodies within a week of having the second dose of the jab.
Higher levels of antibodies likely lead to a stronger immune response which could clear the virus before someone has a chance to spread it, but this is still not proven.
Until now, scientists didn't know whether vaccines would stop transmission and were banking only on it preventing severe illness and death. Pfizer itself has not published any data showing how the jab affects the spread of the disease.
Developers of other vaccines have also not offered any proof that their vaccines will be able to reduce transmission of the virus.
The survey done on 102 hospital staff in Israel is the first indication that a Covid-19 vaccine may stop transmission. It saw all but two of them develop antibody levels that were even higher than patients who had recovered from Covid-19.
Antibodies are substances produced by the immune system which store memories of how to fight off a specific virus.
Study leader Professor Gili Regev-Yochay said the results were 'encouraging and reasonable to assume that these people will not be carriers or contagious, although that is still not a direct conclusion,' the International Business Times reported.
Medics running the study found that 100 out of 102 people mounted large antibody responses to the coronavirus after two doses of the vaccine. The research was done on members of staff at the Sheba Medical Centre in Tel Aviv.
One of the two who didn't had a compromised immune system; the other is still being investigated, The Telegraph reports.
The main purpose of the Covid-19 vaccines when they were developed was to give people some early immunity against the virus so they wouldn't end up in hospital or die if they caught it.
The jabs developed so far have all shown signs of being able to do this and are being rolled out to try and stem the tide of deaths caused by Covid.
But if the vaccines produce a strong enough immune response they could also stop the virus from spreading by training people's bodies to destroy it on sight.
Immunity developed by vaccines is based on substances called antibodies and also other types of immune substances such as white blood cells.
These destroy the virus when it gets into the body, stopping it from reproducing and entering the body to cause infection.
Any amount of this protection will likely reduce the risk of illness and death because it reduces how much of the virus can get into the body, but a weak response might allow the virus to linger in the body for a short period of time, during which people might be infectious to others even if they don't get ill themselves.
A strong immune response from a highly effective vaccine, however, could make the body so good at destroying the virus that all of it gets eliminated as soon as it enters the body of a vaccinated person.
This could mean it exists for too short a period of time for the person to breathe it out and spread it to other people.
None of the vaccine-makers have yet published data showing whether this will be the case.
Antibodies are critical for the immune system because they both destroy viruses and also flag them up for destruction by other white blood cells.
The director of the hospital's Infectious Disease Epidemiology Unit, Professor Regev-Yochay, said she thought it was unlikely that people who receive two doses of jab would spread the illness.
This is expected to be because they develop strong enough immunity that the virus cannot reproduce in their body.
It is possible that if people have vaccines that aren't highly effective, the virus can continue to circulate in their body for a short while without making them ill but still allowing them to pass it on.
Professor Regev-Yochay said in a briefing yesterday: 'The results of the survey are in line with Pfizer’s experiment and even better than expected,' the Jerusalem Post reported.
'I expect that the survey results of the other employees participating will be similar. There is certainly reason for optimism.'
Israel has had one of the world's fastest Covid vaccination programme and has given jabs to 2.6million of its 9million people already.
But the country has yet to see its infection and death numbers come tumbling down after four weeks of immunisations.
Studies from the country suggest the jab could eventually slow the rate of contagion by up to 50 per cent as well as stopping infected recipients becoming sick.
While Israel is leading the world in the vaccine race with more than one in five people receiving an initial dose, its infection rates were last week at their highest ever with more than 8,000 positive tests per day and a record 1,102 patients in hospital.
The vaccine trials run by Pfizer, Moderna, Johnson & Johnson and Oxford University and AstraZeneca had one primary goal which was to try and reduce Covid-19 rates.
To do that, the scientists simply vaccinated half of their volunteers with two doses apiece, and gave the other half two doses of a placebo jab.
They then recorded how many people were diagnosed with Covid-19 after the vaccine, they did not test how much participants caught or transmitted the virus without knowing.
In earlier tests in monkeys, animals that got Pfizer's jab had no traces of the virus in their respiratory tracts, and earlier tests in people showed they produced plenty of antibodies after vaccination.
Combined with the final clinical trial data, that suggests that the vaccine is triggering an immune response, and that immune response is strong enough to keep the virus from copying itself and spreading in the body.
In turn, that means the odds are low that someone's viral load - the concentration of virus in their cells - is high enough to spread the infection.
However the trials that Pfizer completed were not designed to state for sure that the vaccine can slow the spread of the virus.
It comes after nearly 5million people aged between 70 and 80 are being invited to receive their first dose, with some in Whitehall suggesting the rollout is going so well that the wider adult population could be covered by June rather than September.
However, vaccines minister Nadhim Zahawi said people in their 70s will only be offered jabs in areas where the 'majority' of over-80s have already had their first shot.
That could mean people in areas such as London and Suffolk, where progress has been slower, will have to wait longer.
***********************************
Allergies to vaccine rare
Research report just out. Most allergic reactions were in people with other allergies
Allergic Reactions Including Anaphylaxis After Receipt of the First Dose of Pfizer-BioNTech COVID-19 Vaccine
On December 11, 2020, the US Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for the Pfizer-BioNTech coronavirus disease 2019 (COVID-19) vaccine, administered as 2 doses separated by 21 days.1 Shortly after, the Advisory Committee on Immunization Practices (ACIP) issued an interim recommendation for its use.2 Following implementation of vaccination, reports of anaphylaxis after the first dose of the Pfizer-BioNTech COVID-19 vaccine emerged.3 Anaphylaxis is a life-threatening allergic reaction that occurs rarely after vaccination, with onset typically within minutes to hours.4
Notifications and reports of suspected severe allergic reactions and anaphylaxis following vaccination were captured in the Vaccine Adverse Event Reporting System (VAERS), the national passive surveillance (spontaneous reporting) system for adverse events after immunization.5 Physicians at the US Centers for Disease Control and Prevention (CDC) evaluated these reports and applied Brighton Collaboration case definition criteria6 to classify case reports as anaphylaxis or not anaphylaxis. Nonallergic adverse events, mostly vasovagal or anxiety-related, were excluded from the analysis. Anaphylaxis and nonanaphylaxis allergic reaction cases with symptom onset occurring later than the day after vaccination were also excluded because of the difficulty in clearly attributing allergic reactions with delayed onset after vaccination. Because the Moderna COVID-19 vaccine was only available beginning December 21, 2020, this article focuses on the Pfizer-BioNTech COVID-19 vaccine.
During December 14 to 23, 2020, after administration of a reported 1 893 360 first doses of Pfizer-BioNTech COVID-19 vaccine (1 177 527 in women, 648 327 in men, and 67 506 with sex of recipient not reported),3 CDC identified 21 case reports submitted to VAERS that met Brighton Collaboration case definition criteria for anaphylaxis (Table), corresponding to an estimated rate of 11.1 cases per million doses administered. Four patients (19%) were hospitalized (including 3 in intensive care), and 17 (81%) were treated in an emergency department; 20 (95%) are known to have been discharged home or had recovered at the time of the report to VAERS. No deaths from anaphylaxis were reported.
Median interval from vaccine receipt to symptom onset was 13 minutes (range, 2-150 minutes); 15 patients (71%) had onset within 15 minutes; 18 (86%) had onset within 30 minutes.3 The most common symptoms and signs were urticaria, angioedema, rash, and a sense of throat closure. Seventeen (81%) of 21 patients with anaphylaxis had a documented history of allergies or allergic reactions, including to drugs or medical products, foods, and insect stings; 7 (33%) had experienced an episode of anaphylaxis in the past, including one after receipt of rabies vaccine and another after receipt of influenza A(H1N1) vaccine (Table). During the same period, VAERS identified 83 cases of nonanaphylaxis allergic reactions after Pfizer-BioNTech COVID-19 vaccination.3 Commonly reported symptoms in nonanaphylaxis allergic reactions included pruritus, rash, itchy and scratchy sensations in the throat, and mild respiratory symptoms.
Mortality from COVID-19 in populations at high risk is substantial,7 and treatment options are limited. Widespread vaccination against COVID-19 with highly effective vaccines represents an important tool in efforts to control the pandemic. CDC guidance on use of mRNA COVID-19 vaccines8 and management of anaphylaxis is available.9 Specifically, vaccination locations should (1) ensure that necessary supplies are available to manage anaphylaxis, especially sufficient quantities of epinephrine in prefilled syringes or autoinjectors; (2) screen potential vaccine recipients to identify persons with contraindications and precautions; (3) implement recommended postvaccination observation periods, either 15 or 30 minutes depending on each patient’s previous history of allergic reactions; (4) ensure that physicians and other health care professionals can recognize signs and symptoms of anaphylaxis early; and (5) immediately treat suspected anaphylaxis with intramuscular epinephrine (because of the acute, life-threatening nature of anaphylaxis, there are no contraindications to epinephrine administration).
Patients experiencing anaphylaxis should be transported to facilities to receive appropriate medical care. All patients should be instructed to seek immediate medical care if they develop signs or symptoms of an allergic reaction after their observation period ends and they have left the vaccination location. Clinicians have an important role in vaccine safety monitoring by being vigilant in recognizing and reporting adverse events to VAERS
https://jamanetwork.com/journals/jama/fullarticle/2775646
************************************IN BRIEF
Chuck Schumer looking for "power-sharing" agreement with GOP; filibuster is a sticking point (Fox News)
CIA Director Gina Haspel announces resignation (Forbes)
Biden taps "transgender" health official with horrifying COVID nursing home record (PJ Media)
Biden defense nominee blames leaders for failing to root out white supremacy (Examiner)
Court gifts Biden admin a running start by dumping Trump EPA's "Affordable Clean Energy" plan (Roll Call)
Mike Pompeo forces Biden into a corner, says China's policies on Muslims amount to genocide (AP)
Twelve National Guardsmen removed from inaugural duty "out of an abundance of caution" (UPI)
Trump grants Venezuelans 18-month protection from deportation (UPI)
Boston-based political scientist charged with being unregistered agent of Iran (Examiner)
Army soldier, a supporter of ISIS, arrested in plot to blow up 9/11 Memorial (AP)
Study shows extremely low rate of coronavirus transmission in school — 0% from child to adult (Examiner)
German quarantine breakers to be held in refugee camps and detention centers (NY Post)
***********************************
http://snorphty.blogspot.com (TONGUE-TIED)
http://edwatch.blogspot.com (EDUCATION WATCH)
http://antigreen.blogspot.com (GREENIE WATCH)
http://pcwatch.blogspot.com (POLITICAL CORRECTNESS WATCH)
http://australian-politics.blogspot.com/ (AUSTRALIAN POLITICS)
http://awesternheart.blogspot.com.au/ (THE PSYCHOLOGIST)
http://john-ray.blogspot.com (FOOD & HEALTH SKEPTIC) Saturdays only
https://heofen.blogspot.com/ (MY OTHER BLOGS)
*************************************
No comments:
Post a Comment