Filenews 11 August 2020
A candidate vaccine against COVID-19 disease was administered to monkeys and produced an immune response after one dose, according to research published in the journal Nature.
As reported in a report on the World Economic Forum website, researchers at Jansen Vaccines and Prevention, in Lyden, Netherlands, and from Beth Israel Deaconess Medical Center in Boston, Massachusetts, administered a dose of seven different versions of the candidate vaccine to 32 monkeys (rhesus macaques) and 20 a dose of placebo.
The candidate vaccine uses a common cold virus, adenovirus serotype 26 (Ad26) to introduce sars-coV-2's "spike protein" into host cells, where it causes an immune response against SARS-CoV-2, the virus that causes COVID-19.
Six weeks after vaccination all animals were exposed to SARS-CoV-2.
The twenty animals that had received the placebo were infected. The optimal version of the candidate vaccine prevented pulmonary infection in all six animals treated with nasal infection in five of them.
Third-stage trials of the vaccine candidate are expected to begin in September, a process that will include around 30,000 participants and check its effectiveness and safety.
Of a total of 135 candidate vaccines, which are being developed, this will be the seventh to enter the third phase of testing.
Immune response to some common colds may protect against COVID-19
A study published in the journal Science found that certain immune cells that can recognize the coronaviruses caused by the common cold may also react to SARS-CoV-2.
A team from the La Jolla Institute of Immunology in California analyzed immune cells called memory lymphocytes "T" and found that they recognize specific parts of several Sars-CoV-2 proteins. They then identified similar chains in coronaviruses responsible for the common cold and showed that these chains can activate the "T" lymphocytes that can also react to SARS-CoV-2.
Previous studies have found that some people who have never been exposed to SARS-CoV-2 have immune cells that recognize the virus, and this more recent research adds to the theory that immunity to common cold coronaviruses may contribute to differentiation in the severity of COVID-19. However, further investigations are needed.
Confirmation that asymptomatics transmit COVID-19
Moreover, new research published in the journal JAMA Internal Medicine confirms that someone who does not show symptoms of COVID-19 can still transmit the virus.
Until now the evidence that asymptomatic people can transmit the disease has been anecdotal, but a team in South Korea has shown that people who have no symptoms carry the same blood load on their nose, throat and lungs as people who have symptoms and for almost the same amount of time.
The investigation analysed samples taken between 6 and 26 March from 193 symptomatic and 110 asymptomatic people who were in isolation at a community treatment centre in Cheonan, South Korea.
Of the initially symptoms-free patients, 89, around 30% of them, looked healthy during the study, while 21 showed symptoms.
The results of this survey are also in line with statements by covid-19 head in the US Anthony Faucci who has said that "the good news in relation to COVID-19 is that around 40% of the population have no symptoms when infected". But, he added, "even if you're likely not to show symptoms, you're spreading the virus, which means you're going to infect someone who's going to infect someone and then we're going to have serious consequences."
Source: Eyenews / CYPE