Question

• Describe what herd immunity is.
• Find and describe Phase 3 of COVID-19 vaccine testing.
• Based on your knowledge of your family, or friends, or members of your community, describe what people think about receiving the COVID-19 vaccine. What should they see or hear be more convinced to get vaccinated?

Answer 1

· Describe what herd immunity is.

· This provides indirect protection — or herd immunity (also called herd protection)—for those who are not immune to the disease, when most of a population is immune to an infectious disease.

· For example, if 80 percent of a population is immune to a virus, four out of every five people who come across someone with the disease will not get sick (and will not spread the disease anymore). In this way it keeps under control the spread of infectious diseases. Depending on how contagious an infection is, 70 percent to 90 percent of a population usually need immunity to attain herd immunity.

· Find and describe Phase 3 of COVID-19 vaccine testing.

· The transition to clinical trials in Phase 3, stated participants at the workshop, will require some supporting data. Nonclinical animal model data regarding immune response induced by the vaccine should include special consideration of the potential for enhanced respiratory disease (ERD) in vaccinated individuals subsequently exposed to the novel coronavirus.

·
The global pandemic realities mean that data from post-vaccination challenges in non-human primates may not be available to inform a candidate vaccine's ERD risk assessment. Reassuringly, the report notes, preliminary animal data do not show evidence of increased risk of ERD following vaccination with currently in the pipeline vaccines.

·
Earlier-phase clinical data characterising the vaccine-induced immune response should include immune markers for ERD, such as functional versus total antibody response, as well as the ratio of T-helper 1 / T-helper2. If individuals over 55 years of age are included in Phase 3 trials, "preliminary data on safety and immunogenicity from these populations are also required," agreed workshop participants.

· Phase 3 SARS-CoV-2 vaccine trials should be randomised, double-blinded and controlled either with a placebo or an active comparator. If an adaptive study design for a Phase 3 trial is adopted, then adaptation criteria should be pre-specified. In all cases, interim analyses should look for futility, but also for evidence of increased risk of enhanced disease among those vaccinated.

· Endpoints should be standardised across Phase 3 trials to allow an apple-to-apple comparison of vaccine candidates' safety and effectiveness, agreed participants in the workshop. The primary endpoint for all trials should be "of any severity" confirmed in the laboratory by COVID-19 disease, the report says. Hospitalization, mechanical ventilation, and death should be monitored to record severity of illness.

· Previous vaccine research can inform the size of the safety database, the duration of follow-up, and which solicited and unsolicited adverse events are tracked as regards safety assessments. Pre-specified safety criteria should include monitoring for a signal of enhanced disease induced by vaccine, with clear specification of which criteria trigger a pause or stoppage of the trial.

· While safety and efficacy should be key outcomes for individuals who have not been exposed to the novel coronavirus, those designing trials should also plan to expose candidate vaccines as well for those with prior infection, the report noted. This is because it is likely that some individuals with a prior SARS-CoV-2 infection will receive vaccine in the absence of near-universal screening.
Study populations should be racially and ethnically diverse; Phase 3 trials should include older people and those with co-morbidities, agreed participants at the workshops. Safety and immunogenicity data from early-stage studies in younger, healthy participants can provide guidelines for older and more infirm individuals to participate in trials, including those aged 75 and older.

·
Phase 3 trials should be able to determine efficacy in terms of study power across all subgroups, but the design should not require power to determine efficacy at the subgroup level.

· Evaluations of paediatric safety and effectiveness should be planned, as these outcomes can vary from child to adult.

“"Sponsors should provide their plans to accumulate data during pregnancy," the regulators agreed, considering having both pregnant and potentially child-bearing women, and not actively avoiding pregnancy, participate in Phase 3 trials. Decisions on the inclusion of pregnant women should, however, be informed by data on safety and immunogenicity from earlier phase studies involving childbearing women “

The minimum post-vaccination follow-up for COVID-19 outcomes should be one year, so researchers can monitor the duration of the immune response and disease enhancement risk, as well as other safety signals, as antibody titers decrease over time.

· Based on your knowledge of your family, or friends, or members of your community, describe what people think about receiving the COVID-19 vaccine. What should they see or hear be more convinced to get vaccinated?

They can be enlightened about vaccination by having knowledge about following

• In addition to involving individual patients, health care providers are also looking for places where larger groups can be better informed about the benefits of a Covid-19 vaccine. Local parent-teacher association meetings, town halls, or other virtual gatherings in particular offer opportunities for up-to - date and scientifically sound advice.

• Public grassroots outreach campaigns to communities where vaccine hesitation and scepticism predominate. False information spreads out faster on social media than true information. Coupled with government and public health officials' public scepticism, this poses a major challenge.

• In a world where public opinion is dominated by tweets and sound bites, heavy-handed, dry, and regulated government messaging won't work. The messaging must be specifically designed for social media and carried with broad reach by non-traditional messengers, such as local and national celebrities, religious leaders and other influencers.

• In addition to these efforts, social media companies must partner with experts in the field of public health to curb the spread of misinformation, expose the falsehoods that drive vaccine hesitation and stop groups that incite attacks or violence against officials. Wikipedia has leveraged partnerships with the expert reviewers through trusted editors.

• Others have suggested approaches to crowdsourcing to help ensure online claims are genuine. Social media has given us wondrous new, lightning-fast communication tools, and those assets need to drive evidence-based messaging that advances public health and ultimately helps save lives.