Showing posts with label reinfection. Show all posts
Showing posts with label reinfection. Show all posts

Monday 29 March 2021

A city in Brazil’s Amazon rain forest is a stark warning about Covid to the rest of the world

‘Manaus and cities like it will continue to generate dangerous viral variants if vaccination campaigns are not expanded to broadly reach all nations, rich or poor...

‘Manaus was devastated by a first wave of COVID cases beginning last March. Excess deaths—the 3,457 people in the city who died above the expected mortality figures between March 19 and June 24, 2020—represented 0.16 percent of Manaus’s relatively young population. And 7 percent of men older than 75 died at the peak of the spread.

‘Infections were so prevalent that researchers at the University of São Paulo and their colleagues concluded that Manaus was the first city in the world to reach herd immunity—the point at which enough people are immune to a virus that the spread of new infections is hindered. Their preliminary preprint study estimated that 66 percent of the population had been infected with SARS-CoV-2 (they later revised their figure to 76 percent as of October). The threshold for COVID herd immunity is unknown, but projections often cited range from 60 to 90 percent. Similarly high rates of infection have also been found in the Peruvian and Colombian Amazon...

‘In December 2020 a second wave did hit. And by January the city’s health system, which serves communities across the Amazon, had collapsed. ICUs were full to bursting, and oxygen supplies became exhausted. Some patients were airlifted to other regions of Brazil. But many died of asphyxiation on makeshift beds in hospital corridors or their home, doctors say.

‘More severe than the first one, the new wave took Manaus by surprise. Wearing masks and practicing social distancing had been discarded in the belief the city had reached herd immunity. Caseloads surged out of control, and bleak milestones from last year were surpassed. In January alone more than 3,200 excess deaths were logged, Orellana says.’

Read here (Scientific American, Mar 29, 2021)

Thursday 14 January 2021

Past Covid-19 infection may provide 'months of immunity'

‘Most people who have had Covid-19 are protected from catching it again for at least five months, a study led by Public Health England shows. Past infection was linked to around a 83% lower risk of getting the virus, compared with those who had never had Covid-19, scientists found.

‘But experts warn some people do catch Covid-19 again - and can infect others. And officials stress people should follow the stay-at-home rules - whether or not they have had the virus.’

Read here (BBC, Jan 14, 2021) 

Tuesday 27 October 2020

Antibodies ‘fall rapidly after infection’

‘Levels of protective antibodies in people wane "quite rapidly" after coronavirus infection, say researchers. Antibodies are a key part of our immune defences and stop the virus from getting inside the body's cells. The Imperial College London team found the number of people testing positive for antibodies has fallen by 26% between June and September. They say immunity appears to be fading and there is a risk of catching the virus multiple times. The news comes as figures from the Office for National Statistics show that the number of Covid-19 deaths in the UK rose by 60% in the week of 16 October.’

Read here (BBC, Oct 28, 2020)

Read here NEJM paper on Iceland which throws into question this

Coronavirus: Fact checks on immunity and related matters

‘A large study out of the UK suggests immunity after a COVID-19 infection reduces fast, especially among older people. This is a quick fact check on the following: (1) How long am I immune after a COVID-19 infection? (2) Why does research on immunity differ? (3) Do people who have recovered from a COVID-19 infection continue to use protective measures? (4) Do some people, who have had a COVID-19 infection, show no immunity?’

Read here (DW, Oct 28, 2020)

Tuesday 13 October 2020

Covid reinfection: Man gets Covid twice and second hit 'more severe'

‘A man in the United States has caught Covid twice, with the second infection becoming far more dangerous than the first, doctors report. The 25-year-old needed hospital treatment after his lungs could not get enough oxygen into his body. Reinfections remain rare and he has now recovered. But the study in the Lancet Infectious Diseases raises questions about how much immunity can be built up to the virus.’

Read here (BBC, Oct 13, 2020)

Sunday 23 August 2020

First Covid-19 reinfection documented in Hong Kong, researchers say

‘Researchers in Hong Kong on Monday reported what appears to be the first confirmed case of Covid-19 reinfection, a 33-year-old man who was first infected by SARS-CoV-2 in late March and then, four and a half months later, seemingly contracted the virus again while traveling in Europe.

‘The case raises questions about the durability of immune protection from the coronavirus. But it was also met with caution by other scientists, who questioned the extent to which the case pointed to broader concerns about reinfection...

‘During his second infection, the man did not have any symptoms. Some patients go through their course of Covid-19 without showing symptoms, but researchers have also hypothesized that secondary cases of the coronavirus will generally be milder than the first.’

Read here (STAT News, August 24, 2020)

Worst ever Covid variant? Omicron

John Campbell shares his findings on Omicron.  View here (Youtube, Nov 27, 2021)