Vaccine Development Update

Timeline

Oxford AZ vaccine

‘All of the 6 vaccinated monkeys treated with the Oxford vaccine became infected when challenged’

‘That viral loads in the noses of vaccinated and unvaccinated animals were identical’

Less severe clinical symptoms than unvaccinated animals

Neutralising antibody titres were low, insufficient to prevent infection

Insufficient to prevent viral shedding in nasal secretions

Human trials began in April with a non-vaccinated control group

2 groups now undergoing antibody studies

Results in a few months

Now preparing for 30,000 subjects, including elderly and children

New vaccines risk antibody-induced enhancement

This effect caused serious lung damage in animals given experimental vaccines for both SARS-1 and MERS.

Beth Israel Deaconess Medical Center, immunity and vaccine

Two studies,

Infection prevents reinfection.

Prototype vaccines protected against SARS-CoV-2

Antibodies do provide protection, whether they are triggered by an infection or a vaccine.

Study 1

Researchers infected 9 adult monkeys, noses and lungs

Virus quickly spread into their upper and lower respiratory tracts

All 9 developed viral pneumonia

All recovered within 28 days.

A week later, re-exposed, none of the animals got sick

Immunity passports

Study 2

35 monkeys

25 vaccinated (2 doses), 10 not vaccinated

One of six prototypes of DNA vaccines

All prototype vaccines used the genetic code for portions of the protein that CoV-2 uses to invade cells

All of the vaccinated monkeys developed antibodies, some at recovered monkey level

6 candidate DNA vaccines induced neutralizing antibody

3 weeks after the second vaccine dose,

All monkeys inoculated with COVID-19

25 vaccinated and 10 not vaccinated

None of the vaccinated monkeys developed high levels of the virus in their lungs

All 10 of the unvaccinated monkeys did

8 of the 25 vaccinated demonstrated no detectable virus at any point

17 monkeys showed low levels of virus

Higher antibody levels were linked to lower viral loads

Therefore, lab test for risk of infection can be developed

Questions

Does this all apply to humans?

How long will the naturally or vaccine acquired immunity last?