Which of the following can help prevent respiratory infections?

Vaccination against pathogens is a highly effective strategy to help prevent respiratory infections. Vaccines work by stimulating the immune system to recognize specific pathogens, leading to the production of antibodies and activating other immune responses. This preemptive action prepares the body to efficiently combat infections caused by these pathogens if exposure occurs subsequently. For instance, vaccines for influenza and pneumonia have been shown to significantly reduce the incidence and severity of these infections in vaccinated individuals.

The other options do not effectively contribute to the prevention of respiratory infections. Increased exposure to pathogens would actually raise the risk of infection rather than protect against it. Relying solely on over-the-counter medications might alleviate some symptoms but does not prevent infections, and avoiding all contact with other people can have social and psychological consequences without necessarily providing complete protection against infections, as some pathogens can still be contracted in other ways. Thus, vaccination stands out as a proactive and scientifically supported method for preventing respiratory infections.