It will almost inevitably be less successful in older people because the older immune system does not respond as well to immunization. We see this with the annual flu. It may be possible to overcome this by giving multiple doses or by giving it along with a chemical (called an adjuvant) that boosts the immune system.
Who will get the vaccine?
When a vaccine is developed, there will be a limited stock of lots. At least initially. Therefore, it will be important for manufacturers to prioritize deliveries to different countries and segmentation by recipients.
- Medical professionals who come into contact with Covid-19 patients would be first on the list.
- The disease is also the most dangerous for the elderly, so they would be a priority if the vaccine was effective in this age group.
- It is also discussed that it may be better to vaccinate those who live with or care for the elderly.
Coronovirus vaccine candidate shows early success in animal trials
An experimental vaccine protects monkeys from contracting the virus that causes COVID-19. A team led by Chuan Qin at the Beijing Medical College in Beijing injected rhesus monkeys (Macaca mulatta) with three doses of a vaccine consisting of chemically inactivated SARS-CoV-2 particles. Eight monkeys were deliberately exposed to the virus.
All four monkeys receiving the high dose of the vaccine had no detectable virus in their throats or lungs seven days after exposure. The monkeys that received the lower dose of the vaccine showed some signs of coronavirus infection - but their virus levels were much lower than those of the irradiated animals that did not receive the vaccine.
Spit could be the solution to the shortage of coronavirus tests
Human saliva can tell if they are infected with SARS-CoV-2, which could make tests for the virus safer and more affordable. The gold standard for coronavirus testing requires rubbing a long swab into the back of the throat. But these tampons are not enough. Tampons can also induce people to cough or sneeze, which can lead to the formation of many viral particles.
Ann Willie of the Yale School of Public Health in New Haven, Connecticut and her colleagues collected saliva and throat samples from people hospitalized with COVID-19.
The team's testing did not detect the virus in throat swab samples from some patients, but did find it in saliva samples from the same patients. Saliva testing also showed that two health care workers who were doing well and had negative throat tests were actually infected.
Intensive testing detects many silent infections in a small town
According to a study in a small Italian town, a significant proportion of people with COVID-19 are asymptomatic. On February 21, the first COVID-19 death was reported in Bergamo, Italy. This led to the authorities banning movement in the city and stopping public and commercial activities for two weeks. Andrea Crisanti of Imperial College London and his colleagues tested almost every infected person in the city of Bergamo for viral RNA at the beginning and end of the lockdown.
The team found that about 43% of people infected with SARS-CoV-2 in the city reported no fever or other symptoms.
The researchers found no statistically significant difference in potential infectivity between those who reported symptoms and those who did not. The authors say asymptomatic and presymptomatic people play a key role in the transmission of COVID-19, making it difficult to control the disease without strict social distancing.