This article is part four in a series of explainers on vaccine development and distribution. Part one focused on how vaccines work to protect our bodies from disease-carrying germs. Part two focused on the ingredients in a vaccine and the three clinical trial phases. Part three focused on the steps from completing the clinical trial phases through to distribution. This article outlines the different types of vaccines.

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As of December 2020, there are over 200 vaccine candidates for COVID-19 being developed. Of these, at least 52 candidate vaccines are in human trials. There are several others currently in phase I/II, which will enter phase III in the coming months (for more information on the clinical trial phases, see part three of our Vaccine Explained series). …


This article is part three in a series of explainers on vaccine development and distribution. Part one focused on how vaccines work to protect our bodies from disease-carrying germs. Part two focused on the ingredients in a vaccine and the three clinical trial phases. This article outlines the next part of the vaccine journey: the steps from completing the clinical trial phases through to distribution.

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How a vaccine is approved for production

Once a vaccine has reached pre-approval stage following clinical trials, it is assessed by the relevant regulatory body for compliance with quality, safety and efficacy criteria. Following regulatory approval, manufacturers can submit a vaccine to WHO for prequalification (PQ), an assessment process that ensures quality, safety and efficacy and helps the UN and other international procurement organizations determine the programmatic suitability of a vaccine. …


This article is part two in a series of explainers on vaccine development and distribution. Part one focused on how vaccines work to protect our bodies from disease-carrying germs. This article focuses on the ingredients in a vaccine and the three clinical trial phases.

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What are the ingredients in a vaccine?

Vaccines contain tiny fragments of the disease-causing organism or the blueprints for making the tiny fragments. They also contain other ingredients to keep the vaccine safe and effective. These latter ingredients are included in most vaccines and have been used for decades in billions of doses of vaccine.

Each vaccine component serves a specific purpose, and each ingredient is tested in the manufacturing process. …


This article is part one in a series of explainers on vaccine development and distribution. Part one focuses on how vaccines work to protect our bodies from disease-carrying germs. Part two focuses on the ingredients in a vaccine and the three clinical trial phases.

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Germs are all around us, both in our environment and in our bodies. When a person is susceptible and they encounter a harmful organism, it can lead to disease and death.

The body has many ways of defending itself against pathogens (disease-causing organisms). Skin, mucus, and cilia (microscopic hairs that move debris away from the lungs) all work as physical barriers to prevent pathogens from entering the body in the first place. …


Taking stock of all that’s been achieved — and the partnerships working to end the pandemic.

Illustration showing COVID-19 responders
Illustration showing COVID-19 responders

It was the scenario the public health community had feared for decades. A dangerous virus emerges. It spreads rapidly around the world.

COVID-19 infects people when they come together, but coming together is also how we will beat it. 2020 saw the world unite against the virus, from small personal gestures to protect others, to international collaboration on research and innovation. The year ends with COVID-19 vaccines rolling out — an extraordinary feat.

Science, solutions and solidarity have been WHO’s tools for addressing the biggest health threat of the past century — this is the story of the response we built with them. …


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Nurses after an outdoor debriefing meeting at the Mexican Institute of Social Security. © WHO / Lisette Poole

2020 was a devastating year for global health. A previously unknown virus raced around the world, rapidly emerging as one of its top killers, laying bare the inadequacies of health systems. Today, health services in all regions are struggling to both tackle COVID-19, and provide people with vital care.

In another blow, the pandemic threatens to set back hard-won global health progress achieved over the past two decades — in fighting infectious diseases, for example, and improving maternal and child health.

So in 2021, countries around the world will need to continue battle COVID-19 (albeit with the knowledge that effective tools are evolving). They will need to move swiftly to repair and reinforce their health systems so they can deliver these tools, and to address the key societal and environmental issues that result in some sections of the population suffering so much more than others. …


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Dr Mokshanand Fhooblall works with RNA samples extracted from throat swabs at the Candos Virology Lab in Mauritius. © WHO / Gilliane Soupe

Thanks to generous contributions from Member States and other donors, WHO has been supporting countries across all regions with a multi-faceted approach to responding to the pandemic.

Funds provided to WHO are helping slow the spread of COVID-19 in countries all over the world. The support has enabled WHO, amongst others, to ship nearly 300 million items of personal protective equipment to close to 200 countries; strengthen hundreds of national and subnational laboratories with technical support and more than 250 million tests; coordinate the deployment of more than 180 teams and missions to strengthen critical response functions at national and subnational level; deliver 27 million respirators, and support more than 12 000 intensive care beds. …


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WHO volunteer Chisimdi Sobenna Nwogu prepares blood samples for transport at the WHO office in Asaba, Delta State. The samples will be sent to a laboratory in Lagos or Abuja where they can be tested for yellow fever. © WHO / Benedicte Kurzen

In early November 2020, positive samples for yellow fever were reported from five Nigerian states. Nigeria is a high-risk country for yellow fever and is a priority country for the global eliminate yellow fever epidemics (EYE) strategy. The re-emergence of the virus there in September 2017 has been marked by outbreaks throughout the country.

The county has taken great strides toward boosting yellow fever protection and has vaccinated approximately 70 million people through reactive and preventive activities since 2017. However, with COVID-19 response efforts underway, the country’s health system and human resources are being strained, making the response a challenge.

The World Health Organization (WHO) is supporting Nigeria to respond to the outbreak. As of 3 December and since the beginning of the outbreak, a total of 530 suspected and 48 confirmed cases have been reported by the country’s Centre for Disease Control, with 172 deaths among suspected cases, across the five affected states. …


Tobacco causes 8 million deaths every year. When evidence was released this year that smokers were more likely to develop severe disease with COVID-19 compared to non-smokers, it triggered millions of smokers to want to quit tobacco. Quitting can be challenging, especially with the added social and economic stress that have come as a result of the pandemic, but there are a lot of reasons to quit.

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WHO/SEARO

The benefits of quitting tobacco are almost immediate. After just 20 minutes of quitting smoking, your heart rate drops. Within 12 hours, the carbon monoxide level in your blood drops to normal. Within 2–12 weeks, your circulation improves and lung function increases. Within 1–9 months, coughing and shortness of breath decrease. Within 5–15 years, your stroke risk is reduced to that of a non-smoker. Within 10 years, your lung cancer death rate is about half that of a smoker. Within 15 years, your risk of heart disease is that of a non-smoker. …


900 free HIV self-testing kits were sent to 120 locations across Bulgaria, thanks to a pilot project of Single Step Foundation with support from WHO.

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Teodor Paunov demonstrates the use of an HIV self-test in his home in a suburb of Sofia, Bulgaria, on 20 November 2020. © WHO / Blink Media — Nikolay Doychinov

A pilot project conducted in Bulgaria has shown that more people get tested for HIV when self-testing is available. In situations where testing is based in health-care institutions, it can be a challenge to encourage some people to come forward.

“The worries in my community I think come from that many of them are still hidden, not just from their families but also from themselves,” said Teodor Paunov. “And also, the idea that it might happen to someone else, but it will never happen to me, so why would I get tested, I am fine.”

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