COVID-19 is not going away, not now, possibly not ever. “Herd immunity” isn’t possible, and even if it was, politicization of the pandemic engenders misinformation and subsequent widespread opposition to the steps needed to achieve it, causing cycles of uncontrolled outbreaks and needless deaths. Let’s discuss the reasons why these misconceptions persist. Yes, this is an opinion piece, but backed up with references to scientific data.
As a means of reducing the incidence of the disease, “herd immunity,” which some facets of society advocate as the solution, is off the table, because we are not the only herd in the equation: SARS-COV2 has been identified in white-tailed deer, native to most of North America. The deer are not affected by the virus, but are a repository for the virus. This is a well-known disease vector for other zoonotic diseases like Lyme disease, which pass from an animal repository to humans through arachnid bites. Even if all humans are vaccinated against the virus, which—in the present political and world economic environment—is never going to happen, the virus will always be in the environment, lurking in the woods, literally.
The good news is, if vaccination levels in humans is high enough, initial exposure through the animal vector, like the “bird flu” SARS virus of the early 21st Century, would be confined mostly to hunters and wildlife management workers, and can be more easily isolated.
The bad news is, the infection can spread person-to-person if not detected and isolated early. Hunters need to be taught proper handling techniques, but compliance is not likely, considering that hunters tend to be in that segment of the population that currently disregards prophylactic procedures designed to limit spread of the virus, like masks, social distancing, vaccination, and quarantines.
Is it safe? Yes, it is safe: most of the objection on these grounds is fueled by disinformation and extreme exaggeration of the statistics, which include possibly unrelated medical events observed in the vaccinated population, for which there is no correlation.
There is also widespread misunderstanding of how the new technique of using messenger RNA to stimulate antibody production by translating the RNA to the spike protein that is the surface protein of the virus. mRNA is an intermediate product in the molecular biology central dogma pipeline and cannot be translated back into DNA in the body, therefore cannot alter our genomes, nor can it replicate, as the complete virus does after hijacking the replication mechanism of our cells. That part of the virus RNA is missing: only the RNA that translates to the spike protein is present. Hence, the initial reaction to the translated spike protein is controlled, and passes quickly. 
Is it effective? Yes: while cases of vaccinated persons contracting COVID-19 occur at small but statistically significant levels, the vast majority of persons hospitalized with COVID-19 and nearly all of the deaths attributed to the disease have been in the unvaccinated population.  Because the virus is rampant in the population, prudence dictates that we continue to use prophylaxis—hand washing, masks, and social distancing—to reduce probability of exposure, especially in mixed vaccinated/unvaccinated and non-compliant populations.
As far as how long it is effective, studies conducted since widespread use of the vaccine indicates variable loss of efficacy over time among the different formulations, leading to recommendations for booster doses three to six months following initial one- or two-dose vaccinations. Again, this is not unheard of for viral diseases, since viruses mutate rapidly and antibodies naturally dissipate somewhat over time: which is why we get an annual flu vaccination and boosters periodically for other diseases.