Bloomberg) — The vast majority of people who contract Covid-19 still have antibodies at least six months after infection, a new study involving more than 20,000 people showed.
Some 88% of participants who tested positive for a previous infection retained antibodies for six months, according to the report by UK Biobank, a major biomedical database. The number was 99% at three months.
The results follow other, smaller studies that indicate a level of immunity following a natural infection for at least 6 months. Health officials have said it’s still unclear how long protection through vaccines could last, and the rise of mutated virus strains could mean the shots may need to be updated periodically to maintain their efficacy.
The study ran from the end of May through early December, based on monthly blood samples and data on potential symptoms from Biobank participants, their adult children and grandchildren.
The most common symptom associated with having antibodies to Covid was a loss of sense of taste and smell, which was reported by 43% of participants. About a quarter were completely asymptomatic.
AstraZeneca Vaccine Offers Single Dose Protection
The primary analysis of the Phase III clinical trials from the UK, Brazil and South Africa, published as a preprint in The Lancet confirmed COVID-19 Vaccine AstraZeneca is safe and effective at preventing COVID-19, with no severe cases and no hospitalisations, more than 22 days after the first dose.
Results demonstrated vaccine efficacy of 76% (CI: 59% to 86%) after a first dose, with protection maintained to the second dose. With an inter-dose interval of 12 weeks or more, vaccine efficacy increased to 82% (CI: 63%, 92%).
The analysis also showed the potential for the vaccine to reduce asymptomatic transmission of the virus, based on weekly swabs obtained from volunteers in the UK trial. The data showed that PCR positive readings were reduced by 67% (CI: 49%, 78%) after a single dose, and 50% (CI: 38% to 59%) after the two dose regimen, supporting a substantial impact on transmission of the virus.
The primary analysis for efficacy was based on 17,177 participants accruing 332 symptomatic cases from the Phase III UK (COV002), Brazil (COV003) and South Africa (COV005) trials led by Oxford University and AstraZeneca, a further 201 cases than previously reported.
Sir Mene Pangalos, Executive Vice President BioPharmaceuticals R&D, said: “This primary analysis reconfirms that our vaccine prevents severe disease and keeps people out of hospital. In addition, extending the dosing interval not only boosts the vaccine’s efficacy, but also enables more people to be vaccinated upfront. Together with the new findings on reduced transmission, we believe this vaccine will have a real impact on the pandemic.”
Professor Andrew Pollard, Chief Investigator of the Oxford Vaccine Trial, and co-author of the paper, said: “These new data provide an important verification of the interim data that has helped regulators such as the MHRA in the UK and elsewhere around the world to grant the vaccine emergency use authorisation. It also helps to support the policy recommendation made by the Joint Committee on Vaccination and Immunisation for a 12-week prime-boost interval, as they look for the optimal approach to roll out, and reassures us that people are protected 22 days after a single dose of the vaccine.”
COVID-19 Vaccine AstraZeneca, formerly AZD1222
COVID-19 Vaccine AstraZeneca was co-invented by the University of Oxford and its spin-out company, Vaccitech. It uses a replication-deficient chimpanzee viral vector based on a weakened version of a common cold virus (adenovirus) that causes infections in chimpanzees and contains the genetic material of the SARS-CoV-2 virus spike protein. After vaccination, the surface spike protein is produced, priming the immune system to attack the SARS-CoV-2 virus if it later infects the body.
In addition to the programme led by Oxford University, AstraZeneca is conducting a large trial in the US and globally. In total, Oxford University and AstraZeneca expect to enrol up to 60,000 participants globally.
The AstraZeneca COVID-19 vaccine has already been granted a conditional marketing authorisation or emergency use in close to 50 countries, spanning four continents including in the EU, a number of Latin American countries, India, Morocco and the UK.
AstraZeneca (LSE/STO/Nasdaq: AZN) is a global, science-led biopharmaceutical company that focuses on the discovery, development and commercialisation of prescription medicines, primarily for the treatment of diseases in three therapy areas – Oncology, Cardiovascular, Renal & Metabolism, and Respiratory & Immunology. Based in Cambridge, UK, AstraZeneca operates in over 100 countries and its innovative medicines are used by millions of patients worldwide. Please visit astrazeneca.com and follow the Company on Twitter @AstraZeneca.
WHO team visits Wuhan virus lab at center of virus origins speculation; Russia’s Sputnik V vaccine appears safe, effective; US boosts vaccine allotments, financing for virus costs
World Health Organization investigators have visited a research center in the central Chinese city of Wuhan that has been the subject of speculation about the origins of the coronavirus.
The Wuhan Institute of Virology has extensive virus samples, leading to unproven allegations that it may have caused the original outbreak by leaking the virus into the surrounding community, Emily Wang Fujiyama reports from Wuhan.
China has strongly denied that possibility and has promoted also unproven theories that the virus may have originated elsewhere. The WHO team that includes experts from 10 nations has already visited hospitals, research institutes and a traditional wet food market tied to the original outbreak.
Russia Vaccine: Russian scientists say the Sputnik V vaccine appears safe and effective against COVID-19. That’s according to early results of an advanced study published in The Lancet. The news is a boost for the shot that is increasingly being purchased by countries around the world who are desperate to stop the devastation caused by the pandemic. Researchers say their study involved about 20,000 people and showed the vaccine was about 91% effective.
Scientists not linked to the research acknowledged that the quick rollout of the Russian vaccine was criticized for appearing to cut corners. But they said it was now clear that Sputnik V is another effective shot to use in fighting the pandemic, Maria Cheng and Dara Litvinova report.
- Mexico approved Sputnik V following the publication of early results, making it the third vaccine to receive emergency approval in Mexico. The regulating agency approved the Pfizer vaccine in December and AstraZeneca’s in January.
U.S. Vaccines: The Biden administration announced it is moving to expand access to vaccines, freeing up more doses for states and beginning to distribute them to retail pharmacies next week. The push comes amid new urgency to speed vaccinations to prevent the spread of potentially more serious variants of the virus that has killed more than 445,000 Americans, Ricardo Alonso-Zaldivar and Zeke Miller report. Starting next week, 1 million doses will be distributed to 6,500 pharmacies across the country, the White House said.
U.S. Schools: Pressure is building on school systems around the U.S. to reopen classrooms to students who have been learning online for nearly a year. The debate is pitting politicians against teachers who have yet to be vaccinated. In Chicago, there’s so much rancor that teachers are on the brink of striking. In California, a frustrated Gov. Gavin Newsom implored schools to find a way to reopen. In Cincinnati, some students have returned to their classrooms after a judge threw out a teachers union lawsuit over safety concerns, Holly Ramer and Michael Kunzelman report.
Malawi Surge: The southern African country faces a virus resurgence that is overwhelming: a presidential residence and a national stadium have been turned into field hospitals to save lives. President Lazarus Chakwera, just six months in office, lost two Cabinet ministers to COVID-19 in January amid a surge that led him to declare a state of national disaster. Chakwera declared three days of national mourning over the deaths of the ministers and his government ordered a raft of new measures to stem the spread of the virus in a country with a poor health system, Gregory Gondwe reports.
Captain Tom: The World War II veteran who walked into the hearts of a nation in lockdown as he shuffled up and down his garden to raise money for British health care workers has died after testing positive for COVID-19. Capt. Tom Moore was 100. Captain Tom, as he became known as he cheered the country in a dark time, set out to raise 1,000 pounds for Britain’s National Health Service by walking 100 laps of his backyard. But his quest went viral and donations poured in from as far away as the United States and Japan, raising 33 million pounds ($40 million). Danica Kirka has his moving story.
- Authorities have begun testing residents house-by-house in some communities in England as they try to snuff out a new virus variant before it reduces the success of Britain’s nationwide vaccination program. They want to reach 80,000 people in eight areas after the variant first identified in South Africa was found spreading in the country.
- The pressure is on Portugal’s government after almost two weeks at the top of the world rankings of daily new infections and deaths by size of population. Recent missteps include mixed government messages on mask types and online teaching.
- The Palestinian Authority has administered its first known vaccinations after receiving 5,000 Moderna doses from Israel. These will go to front-line Palestinian medical workers.