Risk factors and disease profile of post-vaccination SARS-CoV-2 infection in UK users of the COVID Symptom Study app: a prospective, community-based, nested, case-control study

‘COVID-19 vaccines show excellent efficacy in clinical trials and effectiveness in real-world data, but some people still become infected with SARS-CoV-2 after vaccination. This study aimed to identify risk factors for post-vaccination SARS-CoV-2 infection and describe the characteristics of post-vaccination illness.

‘To minimise SARS-CoV-2 infection, at-risk populations must be targeted in efforts to boost vaccine effectiveness and infection control measures. Our findings might support caution around relaxing physical distancing and other personal protective measures in the post-vaccination era, particularly around frail older adults and individuals living in more deprived areas, even if these individuals are vaccinated, and might have implications for strategies such as booster vaccinations.’

Read here (The Lancet, Nov 1, 2021)

View John Campbell’s video on “Severe illness after vaccination” on the above here.

Sinovac cuts Covid-19 death risk by 84%, AZ and Pfizer by over 90%: Malaysia survey on 1.26m people

‘The Sinovac vaccine can reduce the risk of death among Covid-19 patients by up to 84%, the health ministry said today. Citing data from the real-world evaluation of Covid-19 vaccines under the Malaysia national Covid-19 immunisation programme (RECoVaM), the ministry said the Pfizer jab decreased the risk of death by 93%.

‘In a Twitter post, it said the AstraZeneca vaccine showed the best result, with the lowest rate of “breakthrough deaths”, with the study finding that the jab reduced the risk of deaths among Covid-19 patients by 96%. This was based on a survey led by the health ministry’s Institute for Clinical Research (ICR) on 1,261,270 individuals.’

Read here (Free Malaysia Today, Sept 24, 2021)

Six rules that will define our second pandemic winter

The pandemic keeps changing, but these principles can guide your thinking through the seasons to come.

• The role of vaccines has changed (again)
• The proportion of vaccinated people matters, but who they are and how they cluster also matters
• The people at greatest risk from the virus will keep changing
• As vaccination increases, a higher proportion of cases will appear in vaccinated people—and that’s what should happen
• Rare events are common at scale
• There is no single “worst” version of the coronavirus

Read here (The Atlantic, Sept 20, 2021)

The science behind Covid-19 vaccine boosters: Do we really need an extra shot?

‘The discussion took a new turn this week as fresh data backed up earlier findings - yet to be peer-reviewed - that the efficacy of both Pfizer's and Moderna's vaccines declines in a matter of months, and that one more dose of the Pfizer shot can reduce the rates of infections by 11 times and severe illness by 20 times in the elderly.

‘There are many arguments both for and against boosters, but what concerns policymakers and health professionals first and foremost is whether the science shows that they are a necessity. In considering this, we examine three key issues: Are immunity levels indeed dropping? Will extra shots really help and are they safe? What are the broader implications of giving another shot to those already vaccinated?’

Read here (Straits Times, Sept 19, 2021)

Covid-19 deaths among vaccinated rare, mostly Sinovac recipients

‘These deaths of the fully vaccinated, that occurred between June 7 and Sept 6, were mainly senior citizens (744; 80.6 percent), had comorbidities (750; 81.3 percent) - usually both (605; 65.6 percent). Deaths among those below 60 with no comorbidities only accounted for 33 cases (3.6 percent).

‘Based on Malaysiakini's analysis of the data, Sinovac vaccine recipients account for 710 out of 922 of these deaths (77.0 percent), even though Sinovac vaccine recipients only make up 51.5 percent of fully vaccinated people as of Sept 6 including the 14-day period after the second dose. In comparison, Pfizer vaccine recipients account for 206 deaths (22.3 percent) while accounting for 43.6 percent of the fully vaccinated population in Malaysia. 

‘In other words, there are 10.11 vaccine breakthrough deaths for every 100,000 people fully vaccinated with the Sinovac vaccine, and 3.47 per 100,000 for Pfizer recipients.’

Read here (Malaysiakini via YahooNews, Sept 10, 2021) 

WHO more doubtful about vaccines ending pandemic

‘The head of WHO Europe was today pessimistic about vaccines’ ability to put an end to the Covid pandemic, as new variants dash hopes of reaching herd immunity. Faced with the possibility that the virus may be around for many years, health officials must now “anticipate how to gradually adapt our vaccination strategy”, in particular on the question of additional doses, Hans Kluge told reporters.’

Read here (Free Malaysia Today, Sept 10, 2021)

What we actually know about waning immunity

‘Vaccines don’t last forever. This is by design: Like many of the microbes they mimic, the contents of the shots stick around only as long as it takes the body to eliminate them, a tenure on the order of days, perhaps a few weeks.

‘What does have staying power, though, is the immunological impression that vaccines leave behind. Defensive cells study decoy pathogens even as they purge them; the recollections that they form can last for years or decades after an injection. The learned response becomes a reflex, ingrained and automatic, a “robust immune memory” that far outlives the shot itself, Ali Ellebedy, an immunologist at Washington University in St. Louis, told me. That’s what happens with the COVID-19 vaccines, and Ellebedy and others told me they expect the memory to remain with us for a while yet, staving off severe disease and death from the virus at extraordinary 

‘That prediction might sound incompatible with recent reports of the “declining” effectiveness of COVID-19 vaccines, and the “waning” of immunity. According to the White House, we’ll all need boosters very, very soon to fortify our crumbling defenses. The past few weeks of news have made it seem as though we’re doomed to chase SARS-CoV-2 with shot after shot after shot, as if vaccine protections were slipping through our fingers like so much sand.’

Read here (The Atlantic, Sept 3, 2021)

These charts show that Covid-19 vaccines are doing their job

‘While the vaccines don’t protect against infection as well as they do against severe disease, the shots are keeping people off ventilators and from dying, Kathryn Edwards, an infectious disease pediatrician at Vanderbilt University School of Medicine in Nashville, said August 26 in a news briefing sponsored by the Infectious Diseases Society of America. “We cannot lose the forest for the trees.”

Read here (ScienceNews, Aug 31, 2021)

Highly vaccinated Israel is seeing a dramatic surge in new Covid Cases. Here's why

‘Israel was the first country on Earth to fully vaccinate a majority of its citizens against COVID-19. Now it has one of the world's highest daily infection rates — an average of nearly 7,500 confirmed cases a day, double what it was two weeks ago. Nearly one in every 150 people in Israel today has the virus.

‘What happened, and what can be learned about the vaccine's impact on a highly vaccinated country? Here are six lessons learned — and one looming question for the future of the pandemic.’

1. Immunity from the vaccine dips over time.
2. The delta variant broke through the vaccine's waning protection.
3. If you get infected, being vaccinated helps.
4. Israel's high vaccination rate isn't high enough.
5. Vaccinations are key, but they are not enough.
6. Booster shots offer more protection — if you are one of the world's lucky few to get them.

Looming question: Will we need COVID-19 vaccines every several months? We don't know.

Read here (NPR, August 20, 2021)

Delta has changed the pandemic risk calculus

‘Vaccination was a reprieve from this calculus of personal danger, at least for a while—get vaccinated, get your family and friends vaccinated, get back to a far more normal version of life. To a certain extent, that logic holds: The vaccines are still doing a fantastic job preventing hospitalization and death from the coronavirus’s far-more-transmissible Delta variant. But as COVID-19 cases and hospitalizations have roared back, concerns about breakthrough cases among the vaccinated and increased transmissibility among kids have muddied a lot of people’s ability to gauge their own day-to-day risk, just as they’d begun to venture back out into the world and hug, eat, and laugh in the same airspace together again. In some ways, pandemic life is more confusing than ever.’

Read here (The Atlantic, August 19, 2021)

Indonesia study finds China's Sinovac COVID-19 vaccine effective in medical staff

‘China's Sinovac Biotech COVID-19 vaccine was 98 per cent effective at preventing death and 96 per cent effective at preventing hospitalisation among a group of inoculated Indonesian medical staff, a study conducted by the country's health ministry has found.

‘The findings were based on data from 120,000 healthcare workers in Jakarta who had received the vaccine between January and March this year, lead researcher and health official Pandji Dhewantara told a briefing on Wednesday.’

Read here (Channel News Asia, May 12, 2021)

How a small city in Brazil may reveal how fast vaccines can curb Covid-19

‘The city of Serrana in Brazil is a living experiment. The picturesque place, surrounded by sugarcane fields, is nestled in the southeast of one of the countries hit hardest by COVID-19. By the end of March, daily deaths in Brazil surged to 3,000 on average a day, a high in a pandemic that has claimed more than 405,000 lives there — the second worst death toll of any country in the world behind only the United States. And as vaccines slowly trickle into the country, only about 15 percent of the population has gotten at least one shot.

‘Except in Serrana. There, nearly all the adults have gotten their shots. What happens next in this city could provide a glimpse of what the future of the pandemic could be — not only in Brazil but across the globe as vaccinations pick up.’

Read here (Science News, May 5, 2021)

Why the world should worry about India

‘The world’s largest vaccine producer is struggling to overcome its latest COVID-19 surge—and that’s everyone’s problem...

‘None of the Indian government’s missteps absolve the world from caring about what happens to the country, nor should they. Beyond the obvious moral reasons are practical ones too. As I have repeatedly written before, uncontrolled outbreaks anywhere pose a threat everywhere, including vaccine-rich countries such as the United States. Perhaps the biggest concern right now, in India and elsewhere, is the threat posed by more transmissible variants and their potential ability to overcome vaccine immunity. Though virtually every known variant, including those from Britain, Brazil, and South Africa, has been identified in India, in some states the Indian strain has become the most prevalent.

“It’s very similar to what we saw in Manaus,” Christina Pagel, the director of clinical operational research at University College London, told me, referring to the badly hit Brazilian city. She noted that “it’s not a coincidence that these variants are arising in populations that have developed immunity through infection.”

Read here (The Atlantic, Apr 26, 2021)

China’s Sinovac Covid-19 vaccine 67% effective in preventing symptomatic infection: Chile govt report

‘China's Sinovac COVID-19 vaccine was 67% effective in preventing symptomatic infection, data from a huge real-world study inChile has shown, a potential boost for the jab which has come under scrutiny over its level of protection against the virus.

‘The CoronaVac vaccine was 85% effective in preventing hospitalizations and 80% effective in preventing deaths, the Chilean government said in a report, adding that the data should prove a "game changer" from the vaccine more widely.’

Read here (Reuters, Apr 17, 2021)

CDC finds less than 1 percent of fully vaccinated people got Covid-19

‘The Centers for Disease Control and Prevention (CDC) said the agency has documented about 5,800 “breakthrough” COVID-19 cases among the millions of Americans who are fully vaccinated, totaling far less than 1 percent of fully vaccinated people.

"Vaccine breakthrough infections make up a small percentage of people who are fully vaccinated,” the CDC told The Hill in a statement. “CDC recommends that all eligible people get a COVID-19 vaccine as soon as one is available to them.”

‘The CDC told The Hill on Thursday that about 7 percent of the recorded breakthrough cases resulted in hospitalization and about 1 percent of the people who contracted breakthrough infections died.’

Read here (The Hill, Apr 15, 2021)

Are China’s Covid shots less effective? Experts size up Sinovac

‘The good news is the vaccines work extremely well in combating severe Covid infections, according to Fiona Russell from the Murdoch Children’s Research Institute in Melbourne and Paul Griffin, a professor from the University of Queensland in Brisbane. We asked them key questions about the merits of the Sinovac shot. Their comments have been edited and condensed for brevity.

‘How effective is the Sinovac vaccine really?

‘Russell: The Sinovac study was to look at how the vaccine works against the entire range of clinical symptoms, from mild infections to severe ones, including death. The efficacy data of about 50% is for very mild disease, requiring no treatment. For infections requiring some medical intervention, it’s about 84% and for moderate-to-severe Covid cases, it’s 100%.’

Read here (Bloomberg, Apr 14, 2021)

Indonesia satisfied with effectiveness of Chinese Covid-19 vaccine

‘Indonesia said on Monday (Apr 12) that it is satisfied with the effectiveness of the Sinovac coronavirus vaccine it is using, after the acknowledgement by China’s top disease control official that current vaccines offer low protection against the virus.

‘Siti Nadia Tarmizi, a spokesperson for Indonesia’s COVID-19 vaccine programme, said the World Health Organization had found the Chinese vaccines had met requirements by being more than 50 per cent effective. She noted that clinical trials for the Sinovac vaccine in Indonesia showed it was 65 per cent effective.’

Read here (AP News, Apr 13, 2021)

Vaccines alone will not stop Covid spreading - Here's why

‘Many of us are hoping vaccines against coronavirus will be our route out of lockdown, enabling us to reclaim our old lives. But scientists say jabs alone will not currently be enough and other measures are still needed.’

Read here (BBC, Apr 12, 2021)

Official: Chinese vaccines’ effectiveness low

‘In a rare admission of the weakness of Chinese coronavirus vaccines, the country’s top disease control official says their effectiveness is low and the government is considering mixing them to give them a boost. Chinese vaccines “don’t have very high protection rates,” said the director of the China Centers for Disease Control, Gao Fu, at a conference Saturday in the southwestern city of Chengdu.

‘Beijing has distributed hundreds of millions of doses in other countries while also trying to promote doubt about the effectiveness of Western vaccines. “It’s now under formal consideration whether we should use different vaccines from different technical lines for the immunization process,” Gao said.’

Read here (AP News, Apr 11, 2021)

Why you can't compare Covid-19 vaccines

‘In the US, the first two available Covid-19 vaccines were the ones from Pfizer/BioNTech and Moderna. Both vaccines have very high "efficacy rates," of around 95%. But the third vaccine introduced in the US, from Johnson & Johnson, has a considerably lower efficacy rate: just 66%.

‘Look at those numbers next to each other, and it's natural to conclude that one of them is considerably worse. Why settle for 66% when you can have 95%? But that isn't the right way to understand a vaccine's efficacy rate, or even to understand what a vaccine does. And public health experts say that if you really want to know which vaccine is the best one, efficacy isn't actually the most important number at all.’

View here (Vox, Youtube, Mar 20, 2021)