COVID-19

Coronavirus disease (COVID-19) is an infectious disease caused by the SARS-CoV-2 virus. It emerged as a serious global health threat in late 2019 and still contributes to ongoing mortality in most countries. Australia is currently in its 8th wave of COVID-19 (November 2023).

COVID vaccination was made available in Australia in 2021. Those at high risk of serious disease were given priority vaccination. A course of 2 doses was initially recommended. Over the following 2 years further doses of the vaccine were recommended according to the time lapsed from the previous dose and whether a new strain of the vaccine was available. Research undertaken in the USA suggested that the number of doses of the vaccine was less important than the timing of the last dose. This is particularly important for older Australians where immune senescence plays a large role in reducing the response to a vaccine and length of protection.

The risk of serious COVID-19 disease rests mostly with older people and those with underlying health issues, particularly cardiovascular disease, diabetes, chronic respiratory disease, neurological disease and immune suppression. For any individual, however, infectious disease can have unpredictable outcomes. Young people still die from COVID-19 as they do from influenza.

Most people, particularly those under 70 years old, will experience a mild to moderate upper respiratory tract illness and recover without hospitalisation. In the early stages of the pandemic, before vaccination was available, many more people were hospitalised with serious disease. This percentage has decreased considerably with high rates of vaccination and changing viral strains.

Travellers are at higher risk of exposure to COVID-19. The density of people is generally more than at home and travellers must negotiate congested airports and commuter transport. Many will undertake high exposure activities such as cruising and train or bus travel.

It makes sense to do everything possible to reduce your risk of exposure during travel, as well as minimising your risk of serious disease through vaccination.

Provided you have had at least 2 initial doses of COVID-19 vaccine, it is now believed that the timing of your most recent dose, rather than the number of doses, has the best predictive value for protection. This is especially important for older travellers over 65 years. COVID-19 has a very short incubation period and existing antibodies are very important in reducing the likelihood of serious disease.

Recent immunisation (less than 4-6 months) may be a good way to stay “asymptomatic” when travelling. You will not be welcome at a social event if you have a hacking cough, congestion or fever.

An understanding of respiratory tract illness is important. We know the virus can spread from an infected person as droplets or aerosol when they cough, sneeze, speak, sing or breathe. Keeping a safe distance and wearing a mask in high-risk situations are ways of reducing exposure. Consider others if you have respiratory tract symptoms. These rules apply to all “colds and flu’s” and not just COVID.