Yellow fever definitely. it is an endemic area; vaccine is very effective, has been around for decades, and few people have contraindications (check with a doctor in advance)... and YF is a very nasty disease, with no treatment anywhere in the world - you either get better on your own... or die of multiple organ failure... YF vaccine is good for your lifetime, so no matter where you go in the future, it is out of the way... [babies born in the Amazon and other endemic areas get free YF vaccine when they are 9 months old; that is why you do not see cases in those local populations any more...]

what other vaccines? tetanus is always a good idea anywhere (once every 10 years).

any good doctors/clinics with tropical medicine knowledge in your area? that would be my main source of info, rather than a forum.

Brazil does NOT require any vaccines, but does RECOMMEND yellow fever shot for anyone coming anywhere in Brazil nowadays (after YF started popping in areas which were not endemic too in recent years)... In the event you are going from Brazil to some other tropical country, some of them DO require the intl YF vaccine certificate. And in these cases airlines will NOT allow you to board flight until 10 days AFTER you get the YF shot... In other forums we have seen travelers going from Brazil to Colombia etc who only found that out at airport... and had their trip completely disrupted.

I've been in the same situation so I know exactly the feeling you describe, and it's why I'm a big advocate for PrEP for people who are going to be spending a lot of time in rural or remote areas in particular.

This report, with excerpt below link, illustrates the wisdom of having a pre-exposure vaccination, especially when traveling to higher risk areas. This person received prompt treatment and completed the vaccination regimen, but he did not receive RIG.

https://www.eurosurveillance.org/content/10.2807/ese.17.19.20168-en
“In the case described here, the patient likely lacked of pre-travel consultation, nevertheless he sought and underwent immediate PEP in India. Unfortunately, PEP was incomplete as rabies immunoglobulin was not administered. This was likely the cause of spread to the CNS, which resulted in the patient’s death.”

The British government openly spoke of herd immunity as a goal, some weeks ago.And they were not talking about finding a vaccine.They were talking about letting the virus run through as many people as possible,as quickly as possible! With a number of 'protected groups'sure, but that was the basic theory.

Same for the Dutch.They have both backpedaled on that completely now.The Swedes are not far from changing direction either.

However much you personally like the idea,it has failed as a political measure... nothing to do with whether it is actually effective in the long run,or not. And nothing to do with when/if a vaccine will appear.

Thanks. I just realized that I'll be in Paraguay beforehand, and they might actually ask me for it! Anyone have any ideas about that?

It depends on where you have been in the week or two (the incubation period for YF) before you arrive in Paraguay. As the WHO states:
PARAGUAY
Yellow fever (2019)
Country requirement at entry: a yellow fever vaccination certificate is required for travellers aged 1 year
or over arriving from countries with risk of yellow fever transmission.

We are in Canada too and called around as well when we were going to Bolivia. There is a vaccine shortage and costs varied wildly: 200 to 470 USD per person. Now supposed to be valid for life but a few clinics did indeed tell us that they could only give us a dose valid for a year because of the shortage (those were the ones that were $200).

We were in Colombia in 2017 and did not get vaccinated. Like you, we went to Santa Marta and Minca and to Tayrona. I did a lot of reading and decided the risk of actually getting yellow fever in the Santa Marta area was small enough to risk going without being vaccinated. That was our choice.

By the way, why 2 days in Santa Marta? Santa Marta is not that interesting. I would go to Tayrona (unless you are going in February when Tayrona is closed... in which case I would be tempted to skip Santa Marta).

Have recently heard there might be a connection between being inoculated with BCG as a child and coronavirus. The BCG vaccine was mostly for tuberculosis, but it has been discontinued in some countries (2005 in the U.S., I think). Its formula may also have been slightly different in certain countries.

The VERY LITTLE I heard was that BCG-inoculated people might be more resistant to coronavirus. Perhaps that explains some situations where younger people are more infected than old...??? Would have to compare BCG inoculation history to know more. Just food for thought.

There are several websites that provide info about the requirements such as pet passports, recent health certificate, rabies vaccinations, and two letters from reputable dogs attesting to the good character of your pet.

Are there really no homeless dogs in Turkey already that could use a little loving?

... and there is no way to give a clear 'finishing point',and stick to it.

Well, there is the example of Wuhan, where a very badly spreading infection could be stopped in a certain amount of time with very strict lock-down. I think 1 member of each household was allowed to leave to buy food.

Sure, but that's hardly an en point. Wuhan is still in extreme lock down as the fear is that the moment they relax it it will spread again. It's 'easy' to lock everyone up, but that's not an end solution. The end point is herd immunity, be it naturally by going through the epidemic or be it by vaccination. Wuhan is probably barely, if at all, closer to that point than the severest hit areas in Italy.

Go to the nearest clinic/hospital and ask for it. It is possible that is not available and you have to wait for it. I travel a lot to Africa, and I´m living in Iceland and most of the time you ask where are you going and they check it in the system and will give you an appointment. I paid from 9.000-12.000 ISK per each vaccine and I've Icelandic citizenship so I supposed that if you are a foreigner will be more expensive, check it out too.
You also need the "Yellow card" to show at the entrance of each country the vaccines that you've taken, is mandatory as fieldgate says so please take a copy and travel with the original to our destiny.

Good Luck! and Enjoy Africa!